The determination of MLH1, MSH2, K-ras and MGMT expression was conducted in the serrated lesions and their complicating cancer tissues (experimental group) in the 20 patients with common tubular adenocarcinoma and five cases with colorectal mucosal tissues (control group) as shown in Table III and Fig. 3. The gene discussed is KRAS; the disease is gastric tubular adenocarcinoma.