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). The gene discussed is CEACAM5; the disease is neoplasm.