BRCA1 and ovarian carcinoma: Ovarian cancers with BRCA1/BRCA2 mutations or other HRDs are particularly sensitive to PARP inhibitors because the accumulation of unrepaired DNA breaks leads to cell death (25, 26).This is known as “synthetic lethality”。Niraparib is a highly selective inhibitor of PARP1/2 (a nuclear protein that detects DNA damage and promotes its repair) (27), and the most common adverse effect of niraparib is myelosuppression, with most interruptions of niraparib treatment due to myelosuppressive events (16).