CEACAM5 and cancer: This study was conducted to determine serum levels of some tumor markers, namely carcinoembryonic antigen (CEA), cancer antigen 19-9 (CA19-9) and cancer antigen 72-4 (CA72-4) in patients with chronic H. pylori infections and evaluate the association between serum tumor marker levels and chronic patients with H. pylori infections in Ibb Governorate, Yemen.