However, as a tumor marker, the expression level of CEA increases in both upper gastrointestinal tumors and pancreatic cancer (Yue et al., 2021), and the level of CEA in some tumors is even higher than that in pancreatic cancer (Hasanzadeh et al., 2017; Karimi-Maleh et al., 2021a; Karimi-Maleh et al., 2021b; Karimi-Maleh et al., 2021c). This evidence concerns the gene CEACAM5 and familial pancreatic carcinoma.