BRCA1 and cancer: No somatic PVs were observed in TP53 in CHEK2-deficient cancers (Figure 1, D; Supplementary Figure 3, D, available online), in line with Smid et al. (9), whereas this was the most frequently mutated gene in BRCA1/2-deficient cancers (0/16 vs 24/28; P < .001; Figure 1, D).