REG4 expression was less frequently observed in colorectal cancer than in adjacent non-neoplastic mucosa, in well- and moderately-differentiated adenomas than in mucinous carcinoma (Zheng et al., 2011), and in the cancers of the right colon than in the left colon and rectum, respectively (Kang et al., 2021). The gene discussed is REG4; the disease is cancer.