Multiple synchronous GCs have been reported to account for 5–15% of all GC cases [22] and are associated with older age [23–26], being male [23, 27–29], the macroscopic type (elevated or depressed) [23, 30], the histologic type (differentiation) [24, 25, 31–33], the presence of intestinal mucin [25, 28], severe mucosal atrophy or intestinal metaplasia [25, 28, 34, 35], and submucosal ectopic gastric glands [35]. This evidence concerns the gene MUC3A and gastric cancer.