Pre-B-cell leukemia homeobox 3 (PBX3) is a dominant cofactor in the PBX family, which can increase DNA-binding/transcriptional activity of homeobox (HOX) proteins, and its aberrant overexpression is required for the induction and maintenance of resistant acute myeloid leukemia [5–9]. Here, PBX3 is linked to acute myeloid leukemia.