BRCA2 and malignant colon neoplasm: To further validate the observed resistance in DDR-D cell lines, we evaluated the efficacy of MK-1775 in isogenic cell culture models of recombinantly modified FANCC-null human colon cancer cell line (RKO) and BRCA2-null human colon cancer cell line (DLD1) (Supplementary Fig. S2A and Supplementary Table S6)32, 44.