CEACAM5 and neoplasm: Clinically, the data showed that there was statistical significant positive correlation between H. pylori IgG antibody and tumor markers (CEA, CA19-9 and CA72-4) which was measured by correlation coefficient and linear regression with B = 14.97, 15.70 and 12.91 and r2 = 0.439, 0.287 and 0.582 for CEA, CA19-9, CA72-4 respectively, (Table 3) and (Fig. 3).