More than 40% BRCA1/2-mutant patients fail to respond to PARPi, especially Olaparib, causing minimal synthetic lethality in vitro in BRCA1-mutant human breast cancer HCC1937 and BRCA2-mutant human colorectal adenocarcinoma HCT-15 cells [18,19,20]. Here, BRCA1 is linked to breast carcinoma.