Concerning CD80 expression and function data in gastric cancer, the results of our study revealed an increase in the expression level of the CD80 gene in samples of gastric cancer tumors compared to normal tissues in the microarray metadata analysis, as well as in real-time PCR detection, which revealed a significant increase in the expression level of the CD80 gene in the ACP-03 cell line. This evidence concerns the gene CD80 and gastric cancer.