RUNX1T1 is a putative zinc finger transcription factor and oncoprotein. In acute myeloid leukemia, especially in the M2 subtype, the t(8,21)(q22,q22) translocation is one of the most frequent karyotypic abnormalities. The translocation produces a chimeric gene made up of the 5-region of the RUNX1 gene fused to the 3-region of this gene. The chimeric protein is thought to associate with the nuclear corepressor/histone deacetylase complex to block hematopoietic differentiation. The protein encoded by this gene is a putative zinc finger transcription factor and oncoprotein. In acute myeloid leukemia, especially in the M2 subtype, the t(8,21)(q22,q22) translocation is one of the most frequent karyotypic abnormalities. The translocation produces a chimeric gene made up of the 5-region of the RUNX1 gene fused to the 3-region of this gene. The chimeric protein is thought to associate with the nuclear corepressor/histone deacetylase complex to block hematopoietic differentiation. Several transcript variants encoding multiple isoforms have been found for this gene.