BRCA1 and ovarian cancer: Reversion mutations in HRR genes such as BRCA1, BRCA2, RAD51C, RAD51D, and PALB2 have been observed in ovarian cancer patients who developed PARP inhibitor resistance [39], and the genomic analysis of sequential cfDNA from plasma samples might allow clinicians to follow these genes along with treatment in order to anticipate which patients might have developed resistance.