BRCA1 and esophageal squamous cell carcinoma: Notably, these results were further verified in the 508-WGS ESCC cohort, in which elevated signature 3 contribution was observed in 20 out of 21 ESCCs with germline BRCA1/2 variant but not in tumors harboring somatic mutations in other HR pathway genes (Fig. 4c, Supplementary Fig. 8, Supplementary Fig. 9a).