Quiding-Järbrink et al., [21] shown a decrease in IgA production in the stomach of patients with gastric cancer, suggesting that low levels of antibody production could be an indicative of risk for gastric cancer development in the case of precancerous atrophic gastritis caused by H. pylori. On the other hand, Adamsson et al., [22] found reduced IgA levels in the non-tumor tissue from gastric cancer patients, suggested that this must be used as a marker for the detection of risk cancer group and early stage of gastric cancer. This evidence concerns the gene CD79A and gastric cancer.