PML and acute promyelocytic leukemia: PML::RARA is found in the vast majority of patients with acute promyelocytic leukemia (APL).76,77 In the fusion protein, the N-terminus of the promyelocytic leukemia (PML) protein is fused to the C-terminus of retinoic acid receptor alpha (RARA), resulting in the formation of an aberrant transcriptional regulator.