Signaling pathways, including PI3K-Akt, MAPK, cell cycle, Wnt, and TGF-β, were previously identified as important in the carcinogenesis and development of GC.41 In this study, we identified the somatic variant frequencies of these pathways for both the HDGC cohort (eFigure 5 in Supplement 1) and the TCGA STAD cohort (eFigure 6 in Supplement 1), which revealed distinct profiles. The gene discussed is PIK3CA; the disease is gastric cancer.