The function of RUNX1T1 (RUNX1 partner transcriptional co-repressor 1, Ensembl gene identifier ENSG00000079102) is as follows. Transcriptional corepressor which facilitates transcriptional repression via its association with DNA-binding transcription factors and recruitment of other corepressors and histone-modifying enzymes (PubMed:10688654, PubMed:12559562, PubMed:15203199). Can repress the expression of MMP7 in a ZBTB33-dependent manner (PubMed:23251453). Can repress transactivation mediated by TCF12 (PubMed:16803958). Acts as a negative regulator of adipogenesis (By similarity). The AML1-MTG8/ETO fusion protein frequently found in leukemic cells is involved in leukemogenesis and contributes to hematopoietic stem/progenitor cell self-renewal (PubMed:23812588). {ECO:0000250|UniProtKB:Q61909, ECO:0000269|PubMed:10688654, ECO:0000269|PubMed:10973986, ECO:0000269|PubMed:16803958, ECO:0000269|PubMed:23251453, ECO:0000269|PubMed:23812588, ECO:0000303|PubMed:12559562, ECO:0000303|PubMed:15203199}.