Unifying targeted therapy for leukemia in the era of PARP inhibition

•PARP1 integrates DNA repair pathways and maintains genomic integrity.•Homologous recombination-deficient tumors are sensitive to PARP inhibition.•Epigenetic modulation can induce BRCAness and potentiate PARPi in leukemia cells.•Presence of co-occurring mutations in leukemia subtypes cause resistance to PARPi.•PARPi alone or in combination with targeted therapies are effective in acute myeloid leukemia/myelodysplastic syndrome.