{"entity":{"id":"lyn","kind":"target","name":"LYN kinase","aka":[],"tldr":"LYN is a SRC-family kinase that sits under the B-cell receptor; dasatinib and bosutinib inhibit it alongside BCR-ABL, and LYN over-activity is one way chronic myeloid leukaemia escapes imatinib.","summary":"LYN is a SRC-family tyrosine kinase expressed in B cells and myeloid cells, where it both amplifies and restrains signalling from the B-cell receptor and cytokine receptors. In chronic myeloid leukaemia, over-expression of LYN is a recognised mechanism of imatinib resistance that does not involve a BCR-ABL mutation, and the second-generation inhibitors dasatinib and bosutinib block LYN and other SRC kinases directly. LYN is also constitutively active in chronic lymphocytic leukaemia cells, contributing to their survival.","asOf":"2026-09-04","wikipedia":"https://en.wikipedia.org/wiki/LYN_(gene)","links":[{"label":"UniProt P07948: LYN","url":"https://www.uniprot.org/uniprotkb/P07948/entry"},{"label":"HGNC:6735 LYN","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:6735"},{"label":"ChEMBL target CHEMBL3905","url":"https://www.ebi.ac.uk/chembl/explore/target/CHEMBL3905"}],"tags":["chembl-gap"],"related":["bcr-abl","src"],"cancers":["cml","cll","aml"],"sections":[],"technologies":[],"targets":[],"drugs":["dasatinib","bosutinib"],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"symbol":"LYN","role":[],"sources":[],"specificity":"lineage-antigen","distribution":"one-type","specificityNote":"Lineage antigen shared with normal bone marrow cells and lymphoid tissue cells: HPA finds the gene tissue enhanced in bone marrow, lymphoid tissue, and the 2 medicines aimed at it (Dasatinib, Bosutinib) act on the wild-type protein, so the normal lineage is hit too. HPA LYN: RNA tissue enhanced (bone marrow 70 nTPM, lymphoid tissue 80 nTPM); high antibody staining in 4 normal tissues. Distribution: 1 cancer family in the corpus carries a prevalence row, label threshold or catalogue link for it (Leukaemia); Open Targets associates it with 2 specific cancer types at or above 0.5 (chronic myeloid leukemia, acute lymphoblastic leukemia); the corpus evidence decides and the Open Targets list is quoted for comparison. (Rule 7 of scripts/fetch-target-specificity.ts.)","specificitySources":[{"label":"Human Protein Atlas LYN tissue","url":"https://www.proteinatlas.org/ENSG00000254087-LYN/tissue","note":"RNA tissue and blood lineage specificity, normal tissue antibody staining (version 25.1, CC BY-SA 3.0)"},{"label":"Human Protein Atlas LYN pathology","url":"https://www.proteinatlas.org/ENSG00000254087-LYN/pathology","note":"patients per staining level per cancer type (version 25.1, CC BY-SA 3.0)"},{"label":"Open Targets ENSG00000254087 associations","url":"https://platform.opentargets.org/target/ENSG00000254087/associations","note":"cancer associations at or above 0.5 (CC0)"}],"hgnc":"HGNC:6735","ensembl":"ENSG00000254087","uniprot":"P07948","entrez":"4067","firstDescribed":1987,"firstDescribedBasis":"sequence","firstDescribedNote":"Earliest sequence paper UniProt cites for the protein: Yamanashi et al, Mol. Cell. Biol, 1987, \"The yes-related cellular gene lyn encodes a possible tyrosine kinase similar to p56lck\".","firstDescribedSource":"https://pubmed.ncbi.nlm.nih.gov/3561390/","biology":"A membrane-anchored non-receptor tyrosine kinase; it phosphorylates immunoreceptor tyrosine motifs to start SYK signalling and also activates inhibitory phosphatases, giving it dual roles.","whereFound":["B lymphocytes and myeloid cells","Imatinib-resistant CML and CLL cells"],"targetClass":"kinase","prevalence":[{"cancerId":"metastatic-cancer","pct":"all","measure":"Signalling protein present in most cells (LYN kinase under the B-cell receptor); drugs act on the pathway rather than on a mutation that selects patients, so no prevalence applies."}]},"route":"/targets/lyn/","neighbours":{"target":[{"id":"bcr-abl","kind":"target","name":"BCR::ABL1 (Philadelphia chromosome)","route":"/targets/bcr-abl/"},{"id":"hck","kind":"target","name":"HCK kinase","route":"/targets/hck/"},{"id":"src","kind":"target","name":"SRC family kinases","route":"/targets/src/"}],"cancer":[{"id":"aml","kind":"cancer","name":"Acute myeloid leukaemia","route":"/cancers/aml/"},{"id":"cll","kind":"cancer","name":"Chronic lymphocytic leukaemia","route":"/cancers/cll/"},{"id":"cml","kind":"cancer","name":"Chronic myeloid leukaemia (CML)","route":"/cancers/cml/"}],"drug":[{"id":"bosutinib","kind":"drug","name":"Bosutinib","route":"/drugs/bosutinib/"},{"id":"dasatinib","kind":"drug","name":"Dasatinib","route":"/drugs/dasatinib/"}]}}