Engelsk definition
A TALE-type homeodomain protein and transcription factor that binds the DNA sequence 5'-ATCAATCAA-3'. It forms a heterodimer with MEIS1 TRANSCRIPTION FACTOR and functions as a transcriptional activator of HOMEOBOX PROTEIN NKX-2.5 and ELONGIN A, and as a transcriptional repressor of CDKN2B PROTEIN, in the regulation of developmental and morphogenetic processes such as spleen and limb development. Chromosome translocations involving the PBX1 and TCF3 genes occur in cases of pre-B-cell ACUTE LYMPHOID LEUKEMIA.