Several genes associated with HER2 overexpression—i.e., RARA, MLH1, EGF, ZEB1, VCL, RXRA, WNT1, KLRG1, and SNAIL2—were also differentially expressed in Series 3 (p-value for survival <0.05, Table 2) suggesting their potential association with GC patient’s survival in the general population. This evidence concerns the gene SNAI2 and gastric cancer.