Given the established efficacy of PARP inhibitors in cancers with BRCA1/2 mutation-related homologous recombination deficiencies (HRD) (Bryant et al, 2005; Farmer et al, 2005), we explored the therapeutic potential of DAC against cancer cell lines derived from solid tumors harboring HRD mutations. Here, BRCA1 is linked to hypoparathyroidism-retardation-dysmorphism syndrome.