BRCA1 and ovarian cancer: In addition, miR-622 is highly expressed in BRCA1-deficient high-grade serous ovarian carcinomas (HGSOCs), which can rescue the homologous recombination repair (HRR) defect of BRCA1 mutant ovarian cancer and promote PARPi resistance by regulating the expression of Ku complex and inhibiting HR and non-homologous end joining (NHEJ) (Choi et al., 2016).