ABL1 and acute promyelocytic leukemia: Indeed, synthetic lethality was observed in CML cells with the BCR-ABL1 mutation (BRCA1 downregulated), acute promyelocytic leukemia (APL) cells with the PML-RAR mutation (RAD51C downregulated), and other patient-derived leukemia cells with epigenetic modifications resembling the BRCA-deficient phenotype [84].