CDX2 and gastric cancer: In mammalian cells, caudal type homeobox 2 (CDX2) was found to induce REG4 expression by binding to consensus CDX2-binding elements upstream of the REG4 gene, supported by the positive relationship between CDX2 and REG4 expression in gastric cancer cells and tissues (Naito et al., 2012; Chai et al., 2021).