BRCA1 and cancer: Importantly, among the validated SL gene targets, FANCA emerged as the most frequently disrupted gene in a pan-cancer cohort from The Cancer Genome Atlas, with a prevalence of 2.8% when including deep copy number loss, frameshift, splice-site, or missense mutations, comparable to BRCA1 (2.7%) and BRCA2 (5%) (Fig. 1g).