{"entity":{"id":"fap","kind":"target","name":"FAP","aka":[],"tldr":"FAP (fibroblast activation protein) sits on the cancer-associated fibroblasts that scaffold more than 90% of epithelial cancers and is almost absent from normal adult tissue. FAPI PET tracers therefore light up tumours with high contrast, including pancreatic, gastric and low-grade cancers where FDG PET is weak, and FAP-targeted radioligands are in development.","summary":"Fibroblast activation protein is expressed on cancer-associated fibroblasts in >90% of epithelial cancers, with minimal expression in normal adult tissue. FAPI PET tracers (68Ga-FAPI-46, 18F-FAPI-74) offer high tumour-to-background contrast, including in cancers where FDG is weak (pancreatic, gastric, low-grade). FAP-targeted radioligands (177Lu/225Ac-FAP-2286) are in development.","asOf":"2026-09-04","wikipedia":"https://en.wikipedia.org/wiki/Fibroblast_activation_protein,_alpha","links":[{"label":"Wikipedia","url":"https://en.wikipedia.org/wiki/Fibroblast_activation_protein,_alpha"}],"tags":["theranostic","pet-target","stroma"],"related":[],"cancers":["pancreatic","gastric","tnbc","sarcoma"],"sections":[],"technologies":[],"targets":[],"drugs":["eb-mf-car-nk-01"],"companies":["ratio-therapeutics"],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Pancreatic ductal adenocarcinoma: FAP-positive cancer-associated fibroblasts are the principal source of CXCL12, which coats cancer cells and excludes T cells; depleting them or blocking CXCR4 let T cells in and uncovered the effect of anti-PD-L1 in the autochthonous mouse model (Feig 2013). FAP is also the imaging target of FAPI PET in this stroma-rich disease."],"symbol":"FAP","role":[],"sources":[],"specificity":"immune-microenvironment","distribution":"few-types","specificityNote":"Immune or microenvironment target: the record's class is stroma. HPA FAP: RNA tissue enhanced (endometrium 1 29 nTPM); no normal tissue stained high; highest cancer staining breast cancer (6 of 10 high). Distribution: 4 cancer families in the corpus carry a prevalence row, label threshold or catalogue link for it (Pancreatic ductal adenocarcinoma, Gastric & gastro-oesophageal junction cancer, Breast cancer (all types), Sarcomas (soft tissue, bone, GIST)); Open Targets associates it with 0 specific cancer types at or above 0.5. (Rule 1 of scripts/fetch-target-specificity.ts.)","specificitySources":[{"label":"Human Protein Atlas FAP tissue","url":"https://www.proteinatlas.org/ENSG00000078098-FAP/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"UniProt Q12884","url":"https://www.uniprot.org/uniprotkb/Q12884/entry","note":"involvement in disease"},{"label":"Open Targets ENSG00000078098 associations","url":"https://platform.opentargets.org/target/ENSG00000078098/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:3590","ensembl":"ENSG00000078098","uniprot":"Q12884","entrez":"2191","firstDescribed":1994,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Scanlan M.J. et al, Proc. Natl. Acad. Sci. U.S.A, 1994, \"Molecular cloning of fibroblast activation protein alpha, a member of the serine protease family selectively expressed in stromal fibroblasts of epithelial cancers\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/7911242/","biology":"Serine protease on activated fibroblasts; a stromal target rather than a tumour-cell target, so it is pan-cancer but does not report on the malignant cell itself.","whereFound":["Pancreatic","Gastric","Breast","Sarcoma","Almost all desmoplastic tumours"],"targetClass":"stroma","prevalence":[{"cancerId":"pancreatic","pct":">90","measure":"Stromal FAP by IHC/FAPI PET","source":"https://en.wikipedia.org/wiki/Fibroblast_activation_protein,_alpha","note":"Cancer-associated fibroblasts"},{"cancerId":"gastric","pct":">85","measure":"Stromal FAP","source":"https://en.wikipedia.org/wiki/Fibroblast_activation_protein,_alpha"},{"cancerId":"tnbc","pct":">80","measure":"Stromal FAP","source":"https://en.wikipedia.org/wiki/Fibroblast_activation_protein,_alpha"},{"cancerId":"sarcoma","pct":"60-90","measure":"Tumour and stromal FAP","source":"https://en.wikipedia.org/wiki/Fibroblast_activation_protein,_alpha"}]},"route":"/targets/fap/","neighbours":{"cancer":[{"id":"gastric","kind":"cancer","name":"Gastric & gastro-oesophageal junction cancer","route":"/cancers/gastric/"},{"id":"hcc","kind":"cancer","name":"Hepatocellular carcinoma","route":"/cancers/hcc/"},{"id":"locally-advanced-pdac","kind":"cancer","name":"Locally advanced unresectable pancreatic ductal adenocarcinoma","route":"/cancers/locally-advanced-pdac/"},{"id":"metastatic-pdac","kind":"cancer","name":"Metastatic pancreatic ductal adenocarcinoma","route":"/cancers/metastatic-pdac/"},{"id":"pancreatic","kind":"cancer","name":"Pancreatic ductal adenocarcinoma","route":"/cancers/pancreatic/"},{"id":"sarcoma","kind":"cancer","name":"Sarcomas (soft tissue, bone, GIST)","route":"/cancers/sarcoma/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"drug":[{"id":"eb-mf-car-nk-01","kind":"drug","name":"EB-MF-CAR-NK-01","route":"/drugs/eb-mf-car-nk-01/"},{"id":"fap-2286","kind":"drug","name":"FAP-2286 (177Lu / 68Ga)","route":"/drugs/fap-2286/"}],"company":[{"id":"ratio-therapeutics","kind":"company","name":"Ratio Therapeutics","route":"/companies/ratio-therapeutics/"},{"id":"sofie-biosciences","kind":"company","name":"SOFIE Biosciences","route":"/companies/sofie-biosciences/"}],"term":[{"id":"cancer-associated-fibroblasts","kind":"term","name":"Cancer-associated fibroblasts (CAFs)","route":"/terms/cancer-associated-fibroblasts/"},{"id":"desmoplasia","kind":"term","name":"Desmoplasia (tumour stroma)","route":"/terms/desmoplasia/"},{"id":"immune-exclusion","kind":"term","name":"Immune exclusion","route":"/terms/immune-exclusion/"},{"id":"mechanical-theory-of-cancer","kind":"term","name":"Mechanical theory: stiffness, pressure and force as causes","route":"/terms/mechanical-theory-of-cancer/"},{"id":"microenvironment-inflammation-theory","kind":"term","name":"Microenvironment and inflammation: tumours as wounds that do not heal","route":"/terms/microenvironment-inflammation-theory/"}],"paper":[{"id":"paper-ozdemir-caf-depletion-accelerates-pancreatic-cancer-cancer-cell-2014","kind":"paper","name":"Depletion of carcinoma-associated fibroblasts and fibrosis induces immunosuppression and accelerates pancreas cancer with reduced survival","route":"/key-papers/paper-ozdemir-caf-depletion-accelerates-pancreatic-cancer-cancer-cell-2014/"},{"id":"paper-ohlund-caf-subtypes-mycaf-icaf-jem-2017","kind":"paper","name":"Distinct populations of inflammatory fibroblasts and myofibroblasts in pancreatic cancer","route":"/key-papers/paper-ohlund-caf-subtypes-mycaf-icaf-jem-2017/"},{"id":"paper-feig-cxcl12-fap-cafs-t-cell-exclusion-pnas-2013","kind":"paper","name":"Targeting CXCL12 from FAP-expressing carcinoma-associated fibroblasts synergizes with anti-PD-L1 immunotherapy in pancreatic cancer","route":"/key-papers/paper-feig-cxcl12-fap-cafs-t-cell-exclusion-pnas-2013/"}],"roadmap":[{"id":"cell-therapy-roadmap","kind":"roadmap","name":"Cell therapy roadmap: CD19 CAR-T → solid tumours → in vivo CAR","route":"/roadmaps/cell-therapy-roadmap/"},{"id":"pancreatic-roadmap","kind":"roadmap","name":"Pancreatic cancer roadmap: from Whipple's operation to gemcitabine, FOLFIRINOX, adjuvant chemotherapy, PARP inhibition, KRAS inhibition, vaccines and the surveillance question","route":"/roadmaps/pancreatic-roadmap/"}],"idea":[{"id":"idea-bio2-tumour-anchored-tgfbeta-trap","kind":"idea","name":"Anchor a TGF-beta trap in the tumour stroma so it cannot act everywhere","route":"/ideas/idea-bio2-tumour-anchored-tgfbeta-trap/"},{"id":"idea-bio1-stromal-resistance-blockade","kind":"idea","name":"Block the survival signals the tumour's neighbours provide","route":"/ideas/idea-bio1-stromal-resistance-blockade/"},{"id":"idea-fap-theranostics-pancancer","kind":"idea","name":"FAP theranostics as a pan-cancer stromal strategy","route":"/ideas/idea-fap-theranostics-pancancer/"},{"id":"idea-mced-plus-fapi","kind":"idea","name":"FAPI PET as the workup for MCED positives","route":"/ideas/idea-mced-plus-fapi/"},{"id":"idea-moon-cold-to-hot-programme","kind":"idea","name":"Make every cold tumour hot: a coordinated programme to reprogramme immune-excluded tumours","route":"/ideas/idea-moon-cold-to-hot-programme/"},{"id":"idea-bio2-caf-subtype-assignment","kind":"idea","name":"Match therapy to the type of scar-forming cell in the tumour","route":"/ideas/idea-bio2-caf-subtype-assignment/"},{"id":"idea-pdac-stromal-reprogramming-not-depletion","kind":"idea","name":"Reprogramme the stroma rather than remove it: second-generation stromal trials with a stromal biomarker and a survival endpoint","route":"/ideas/idea-pdac-stromal-reprogramming-not-depletion/"},{"id":"idea-immune-exclusion-drivers","kind":"idea","name":"What actually holds T cells at the tumour border?","route":"/ideas/idea-immune-exclusion-drivers/"}],"technology":[{"id":"stroma-directed-car","kind":"technology","name":"CAR-T against stroma: fibroblasts and myeloid cells","route":"/technologies/stroma-directed-car/"},{"id":"fapi-pet","kind":"technology","name":"FAPI PET","route":"/technologies/fapi-pet/"},{"id":"radioligand-therapy","kind":"technology","name":"Radioligand therapy (beta emitters)","route":"/technologies/radioligand-therapy/"},{"id":"targeted-alpha-therapy","kind":"technology","name":"Targeted alpha therapy","route":"/technologies/targeted-alpha-therapy/"},{"id":"mechanobiology-therapy","kind":"technology","name":"Targeting tumour mechanics and pressure","route":"/technologies/mechanobiology-therapy/"}],"institution":[{"id":"heidelberg-nct","kind":"institution","name":"Heidelberg University Hospital / NCT / DKFZ","route":"/institutions/heidelberg-nct/"},{"id":"uk-duesseldorf","kind":"institution","name":"University Hospital Düsseldorf / CIO Düsseldorf","route":"/institutions/uk-duesseldorf/"}],"person":[{"id":"erik-sahai","kind":"person","name":"Erik Sahai","route":"/people/erik-sahai/"},{"id":"frederik-giesel","kind":"person","name":"Frederik Giesel","route":"/people/frederik-giesel/"},{"id":"ken-herrmann","kind":"person","name":"Ken Herrmann","route":"/people/ken-herrmann/"},{"id":"song-shaoli","kind":"person","name":"Shaoli Song","route":"/people/song-shaoli/"},{"id":"uwe-haberkorn","kind":"person","name":"Uwe Haberkorn","route":"/people/uwe-haberkorn/"}],"bottleneck":[{"id":"b-tme-immunosuppression","kind":"bottleneck","name":"Cold tumours and the immunosuppressive microenvironment","route":"/bottlenecks/b-tme-immunosuppression/"}],"pathway":[{"id":"immune-desert-exclusion","kind":"pathway","name":"Cold tumours: immune deserts and exclusion","route":"/pathways/immune-desert-exclusion/"},{"id":"caf-activation-desmoplasia","kind":"pathway","name":"Fibroblast activation, desmoplasia & matrix stiffness","route":"/pathways/caf-activation-desmoplasia/"},{"id":"invasion-ecm-degradation","kind":"pathway","name":"Invasion: proteases, adhesion & the invasive front","route":"/pathways/invasion-ecm-degradation/"},{"id":"tumor-microenvironment","kind":"pathway","name":"Tumour microenvironment (TME)","route":"/pathways/tumor-microenvironment/"}]}}