{"entity":{"id":"meis1","kind":"target","name":"MEIS1","aka":["Meis homeobox 1"],"tldr":"MEIS1 is HOXA9's partner in keeping leukaemia cells immature. The two are switched on together in KMT2A-rearranged and NPM1-mutant leukaemia, and switched off together when a menin inhibitor works.","summary":"MEIS1 (chromosome 2p14) is a homeobox transcriptional regulator that controls PAX6, activates PF4 in complex with PBX1 or PBX2, is required for haematopoiesis, megakaryocyte lineage development and vascular patterning, and may act as a cofactor for HOXA7 and HOXA9 in the induction of myeloid leukaemias (UniProt O00470). In OnCo it is, with HOXA9, the leukaemia programme downstream of the menin-KMT2A complex that revumenib and ziftomenib silence in KMT2A-rearranged and NPM1-mutant acute leukaemia (ziftomenib mechanism: displacing KMT2A complexes from menin silences HOXA9/MEIS1 and releases the differentiation block).","asOf":"2026-09-22","links":[{"label":"HGNC HGNC:7000","url":"https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:7000"},{"label":"UniProt O00470","url":"https://www.uniprot.org/uniprotkb/O00470/entry"},{"label":"NCBI Gene 4211","url":"https://www.ncbi.nlm.nih.gov/gene/4211"}],"tags":["wave5-target"],"related":["revumenib","ziftomenib","menin","hoxa9","kmt2a","npm1"],"cancers":["aml","all-leukemia","aml-npm1-kmt2a"],"sections":[],"technologies":["menin-inhibitors"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":["menin-kmt2a","aml-signalling"],"terms":[],"trials":[],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":["Prevalence not recorded in this wave: HGNC and UniProt carry no positivity rates and no other source was consulted."],"provenance":{"editedBy":"OnCo content wave 5 (HGNC REST, UniProt REST, corpus drug and pathway records)","editedOn":"2026-09-22"},"symbol":"MEIS1","hgnc":"HGNC:7000","ensembl":"ENSG00000143995","uniprot":"O00470","entrez":"4211","biology":"Like HOXA9, MEIS1 is a transcription factor without a direct inhibitor in the corpus; its fall after menin inhibition is the mechanism step the revumenib and ziftomenib records describe.","whereFound":["KMT2A-rearranged acute leukaemia","NPM1-mutant AML","Haematopoietic stem cells and megakaryocyte lineage (normal function)"],"targetClass":"transcription","prevalence":[]},"route":"/targets/meis1/","neighbours":{"drug":[{"id":"revumenib","kind":"drug","name":"Revumenib","route":"/drugs/revumenib/"},{"id":"ziftomenib","kind":"drug","name":"Ziftomenib","route":"/drugs/ziftomenib/"}],"target":[{"id":"hoxa9","kind":"target","name":"HOXA9","route":"/targets/hoxa9/"},{"id":"kmt2a","kind":"target","name":"KMT2A (MLL) rearrangement","route":"/targets/kmt2a/"},{"id":"menin","kind":"target","name":"Menin","route":"/targets/menin/"},{"id":"npm1","kind":"target","name":"NPM1 mutation","route":"/targets/npm1/"}],"cancer":[{"id":"all-leukemia","kind":"cancer","name":"Acute lymphoblastic leukaemia","route":"/cancers/all-leukemia/"},{"id":"aml","kind":"cancer","name":"Acute myeloid leukaemia","route":"/cancers/aml/"},{"id":"aml-npm1-kmt2a","kind":"cancer","name":"NPM1-mutated and KMT2A-rearranged acute myeloid leukaemia","route":"/cancers/aml-npm1-kmt2a/"}],"technology":[{"id":"menin-inhibitors","kind":"technology","name":"Menin inhibitors","route":"/technologies/menin-inhibitors/"}],"pathway":[{"id":"aml-signalling","kind":"pathway","name":"Acute myeloid leukaemia (KEGG map)","route":"/pathways/aml-signalling/"},{"id":"menin-kmt2a","kind":"pathway","name":"Menin / KMT2A (HOXA9-MEIS1 axis)","route":"/pathways/menin-kmt2a/"}]}}