Moreover, we validated the correlations between the ICD genes and the tumor microenvironment in pan‐cancer and captured some key genes, such as CD4, CD8A, CD8B, CXCR3, FOXP3, PRF1, and IFNG, which shared strong relationships with the tumor microenvironment, immune cell infiltration, and immune checkpoints. This evidence concerns the gene CD8A and neoplasm.