{"entity":{"id":"ptk6","kind":"target","name":"PTK6 (BRK)","aka":[],"tldr":"PTK6, also called breast tumour kinase, is over-expressed in most breast cancers and is one of the off-targets of dasatinib; drugs made specifically against it are still experimental.","summary":"Protein tyrosine kinase 6, or breast tumour kinase (BRK), is a distant relative of the SRC family that is normally found in differentiating gut and skin epithelium but is over-expressed in the majority of breast cancers and in some colon, prostate and ovarian tumours, where it promotes proliferation, survival and migration through STAT3 and AKT. It appears in ChEMBL as a target because approved multi-kinase inhibitors, dasatinib among them, inhibit it; selective PTK6 inhibitors and degraders are in preclinical development, including for HER2-positive and triple-negative breast cancer.","asOf":"2026-09-04","wikipedia":"https://en.wikipedia.org/wiki/PTK6","links":[{"label":"UniProt Q13882: PTK6","url":"https://www.uniprot.org/uniprotkb/Q13882/entry"},{"label":"HGNC:9617 PTK6","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:9617"},{"label":"ChEMBL target CHEMBL4601","url":"https://www.ebi.ac.uk/chembl/explore/target/CHEMBL4601"}],"tags":["chembl-gap"],"related":["her2","egfr","src"],"cancers":["breast-her2-positive","tnbc","colorectal","prostate"],"sections":[],"technologies":[],"targets":[],"drugs":["dasatinib"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"PTK6","role":[],"sources":[],"specificity":"tumour-associated","distribution":"few-types","specificityNote":"Tumour-associated overexpression: HPA finds the RNA tissue enhanced in normal esophagus, skin 1, vagina, so the tumour and the normal tissue it comes from share the target and the medicine relies on the difference in level. HPA PTK6: RNA tissue enhanced (esophagus 104 nTPM, skin 1 51 nTPM, vagina 41 nTPM); high antibody staining in 3 normal tissues; highest cancer staining stomach cancer (1 of 12 high). Distribution: 3 cancer families in the corpus carry a prevalence row, label threshold or catalogue link for it (Breast cancer (all types), Colorectal cancer, Prostate cancer); Open Targets associates it with 1 specific cancer type at or above 0.5 (medullary thyroid gland carcinoma). (Rule 7 of scripts/fetch-target-specificity.ts.)","specificitySources":[{"label":"Human Protein Atlas PTK6 tissue","url":"https://www.proteinatlas.org/ENSG00000101213-PTK6/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"Human Protein Atlas PTK6 pathology","url":"https://www.proteinatlas.org/ENSG00000101213-PTK6/pathology","note":"patients per staining level per cancer type (version 25.1, CC BY-SA 3.0)"},{"label":"Open Targets ENSG00000101213 associations","url":"https://platform.opentargets.org/target/ENSG00000101213/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:9617","ensembl":"ENSG00000101213","uniprot":"Q13882","entrez":"5753","firstDescribed":1994,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Mitchell P.J. et al, Oncogene, 1994, \"Cloning and characterisation of cDNAs encoding a novel non-receptor tyrosine kinase, brk, expressed in human breast tumours\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/8036022/","biology":"An intracellular non-receptor tyrosine kinase lacking a membrane anchor; in tumours it phosphorylates STAT3, paxillin and Sam68 and cooperates with HER2 and EGFR signalling.","whereFound":["Differentiated intestinal and skin epithelium","Most breast cancers; some colon, prostate and ovarian cancers"],"targetClass":"kinase","prevalence":[{"cancerId":"metastatic-cancer","pct":"all","measure":"Signalling protein present in most cells (PTK6, over-expressed in many breast cancers without a selecting mutation); drugs act on the pathway rather than on a mutation that selects patients, so no prevalence applies."}]},"route":"/targets/ptk6/","neighbours":{"target":[{"id":"egfr","kind":"target","name":"EGFR","route":"/targets/egfr/"},{"id":"her2","kind":"target","name":"HER2","route":"/targets/her2/"},{"id":"src","kind":"target","name":"SRC family kinases","route":"/targets/src/"}],"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"},{"id":"breast-her2-positive","kind":"cancer","name":"HER2-positive breast cancer","route":"/cancers/breast-her2-positive/"},{"id":"prostate","kind":"cancer","name":"Prostate cancer","route":"/cancers/prostate/"},{"id":"tnbc","kind":"cancer","name":"Triple-negative breast cancer (TNBC)","route":"/cancers/tnbc/"}],"drug":[{"id":"dasatinib","kind":"drug","name":"Dasatinib","route":"/drugs/dasatinib/"}]}}