Here, we first identified a novel chromosomal dic(7;9) (p13;p13) translocation in a Ph-positive mixed phenotype acute leukemia (MPAL) patient, resulting in a PAX5 out-of-frame fusion with the ubiquitin-conjugating enzyme E2D4 (UBE2D4), which functions as a truncated PAX5. Here, PAX5 is linked to mixed phenotype acute leukemia.