{"entity":{"id":"frk","kind":"target","name":"FRK kinase","aka":[],"tldr":"FRK is a SRC-related kinase that mostly acts as a brake on growth; it is a minor off-target of approved kinase inhibitors and is lost or mutated in some liver and brain cancers.","summary":"Fyn-related kinase (FRK) is a non-receptor tyrosine kinase of the SRC family that, unusually for the family, behaves as a tumour suppressor in several tissues: it stabilises PTEN, and its loss is reported in glioma, hepatocellular carcinoma and breast cancer. It is listed as a target of approved drugs because multi-kinase inhibitors such as dasatinib bind it, rather than because inhibiting it is the goal. Activating FRK fusions and mutations have been described in a minority of liver cancers, where kinase inhibition may be relevant.","asOf":"2026-09-04","wikipedia":"https://en.wikipedia.org/wiki/FRK_(gene)","links":[{"label":"UniProt P42685: FRK","url":"https://www.uniprot.org/uniprotkb/P42685/entry"},{"label":"HGNC:3955 FRK","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:3955"},{"label":"ChEMBL target CHEMBL4223","url":"https://www.ebi.ac.uk/chembl/explore/target/CHEMBL4223"}],"tags":["chembl-gap"],"related":["src"],"cancers":["glioblastoma","hcc"],"sections":[],"technologies":[],"targets":[],"drugs":["dasatinib"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"FRK","role":[],"sources":[],"specificity":"broadly-expressed","distribution":"few-types","specificityNote":"Broadly expressed or essential: HPA finds the RNA at low tissue specificity; the 1 medicine aimed at it (Dasatinib) act on the wild-type protein, so normal tissue is exposed and the therapeutic window comes from the tumour's faster division or its dependence on the protein. HPA FRK: RNA low tissue specificity; high antibody staining in 4 normal tissues; highest cancer staining liver cancer (2 of 12 high). Distribution: 2 cancer families in the corpus carry a prevalence row, label threshold or catalogue link for it (Brain and spinal cord tumours (all types), Hepatocellular carcinoma); Open Targets associates it with 3 specific cancer types at or above 0.5 (chronic myeloid leukemia, colorectal cancer, acute lymphoblastic leukemia). (Rule 7 of scripts/fetch-target-specificity.ts.)","specificitySources":[{"label":"Human Protein Atlas FRK tissue","url":"https://www.proteinatlas.org/ENSG00000111816-FRK/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"Open Targets ENSG00000111816 associations","url":"https://platform.opentargets.org/target/ENSG00000111816/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:3955","ensembl":"ENSG00000111816","uniprot":"P42685","entrez":"2444","firstDescribed":1993,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Cance W.G. et al, Int. J. Cancer, 1993, \"Novel protein kinases expressed in human breast cancer\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/8099900/","biology":"A nuclear and cytoplasmic SRC-family kinase expressed in epithelial tissues, brain and liver; it phosphorylates PTEN and retinoblastoma protein, slowing the cell cycle.","whereFound":["Epithelial tissues, brain and liver","Reduced in glioma, hepatocellular carcinoma and some breast cancers"],"targetClass":"kinase","prevalence":[{"cancerId":"metastatic-cancer","pct":"all","measure":"Signalling protein present in most cells (FRK kinase); drugs act on the pathway rather than on a mutation that selects patients, so no prevalence applies."}]},"route":"/targets/frk/","neighbours":{"target":[{"id":"src","kind":"target","name":"SRC family kinases","route":"/targets/src/"}],"cancer":[{"id":"glioblastoma","kind":"cancer","name":"Glioma & glioblastoma","route":"/cancers/glioblastoma/"},{"id":"hcc","kind":"cancer","name":"Hepatocellular carcinoma","route":"/cancers/hcc/"}],"drug":[{"id":"dasatinib","kind":"drug","name":"Dasatinib","route":"/drugs/dasatinib/"}]}}