CD8A and malignant colon neoplasm: Taken together, these results disclosed that the GSTM2 mRNA expression was correlated to the immune scores, and universally associated with the infiltration levels of five types of immune cells, including B cell, T cell CD8+, T cell CD4+, macrophage, dendritic cell, which further indicated that GSTM2 was a potentially regulatory gene for immune microenvironment of colon cancer.