Notably, reduced RNF43 function is a negative prognosis factor in gastric cancer patients (Gao et al., 2017; Neumeyer et al., 2019a; Niu et al., 2015) and RNF43 loss-of-function type of mutation exacerbated Helicobacter pylori-induced gastric tumor carcinogenesis associated with the upregulation of WNT5A mRNA level (Katoh, 2007; Li et al., 2014; Neumeyer et al., 2019b; Peek and Crabtree, 2006). This evidence concerns the gene RNF43 and gastric cancer.