In our previous study, investigators found that serum HDL-C and LDL-C levels were associated with the risk, resectability, and prognosis of gastric cancer. There are several cohort studies reported that low serum cholesterol levels are associated with incident cancer, including gastric cancer. However, most studies regarding the serum cholesterol and gastric cancer investigated gastrectomized patients, and showed the association between low serum cholesterol levels and lymph node metastasis or submucosal invasion. Furthermore, there are only few studies evaluated the association between LDL-C of apolipoproteins and gastric cancer. Therefore investigators conducted nested case-control study to investigate the association between serum cholesterol levels including TC, HDL-C, LDL-C, triglyceride (TG), apolipoproteins and gastric neoplasm. In addition, further analyses were performed to evaluate the possible role of the serum cholesterol as a predictor for the differentiation and prognosis of gastric neoplasm.