Moreover, the loss of ARH3 increased PARPi resistance in triple-negative breast cancer (TNBC) SUM149PT (BRCA1 mutant, BRCA2-WT) and SUM159PT (BRCA1/2-WT) cells (Figures 3H, S3K, and S3L). The gene discussed is BRCA1; the disease is triple-negative breast carcinoma.