We selected the DLD-1 human colorectal carcinoma cell line for its normal karyotype and a high mutagenic rate due to microsatellite instability,22 and the SUM149PT BRCA1 mutant triple-negative breast carcinoma cell line for highest relevance to PARPI treatment and no detectable BRCA1 protein.23,24. The gene discussed is BRCA1; the disease is colorectal carcinoma.