BRCA1 and cancer: However, with the recent advent of PARP inhibitors, which are expected to be effective against HRR-deficient cancer, and the popularity of genetic testing that detects HBOCs other than those with BRCA1/2 mutations, the current status of clinical practice, the 2020 version 1 called the “Approach To Cancer History” for all patients, has been revised to include recommendations for a more comprehensive approach for subjects who request genetic testing for HBOC-related genes (Fig. 2).