In ovarian carcinogenesis, REG4 mRNA and protein levels were higher in ovarian tumors than in normal ovaries, in mucinous carcinomas than in serous carcinomas, and in well- and moderately-differentiated carcinomas than in poorly-differentiated carcinomas, respectively (Chen et al., 2015), in line with another report (Xiang et al., 2022). This evidence concerns the gene REG4 and mucinous adenocarcinoma.