Among these genes, MUC16 (eFigure 10B in Supplement 1) is a known oncogene annotated in the COSMIC database, and multivariate Cox proportional hazzards regression analysis revealed that the germline alterations of NCKAP5 (eFigure 10C in Supplement 1), HSPG2 (eFigure 10D in Supplement 1), and FSIP2 (eFigure 10E in Supplement 1) were independent factors associated with clinical outcomes of patients with HDGC (eFigure 10F-H in Supplement 1). Here, HSPG2 is linked to Familial gastric cancer.