Notably, as observed with the breast cancer cell lines, the PARPi sensitivity signature accurately predicted the response of the two PARP-resistant BRCA1/2 mutants that had gained additional mutations (STG316 with mutant TP53BP130 and VHI0179 with mutant REV7)31 reversing their HR defective phenotype. The gene discussed is MAD2L2; the disease is breast carcinoma.