A combination of oral AHCC® and dual immune checkpoint blockade (DICB), including PD-1/CTLA-4 blockade, had reduced tumor growth and increased granzyme B and Ki-67 expression by tumor-infiltrating CD8+ T cells in MC38 colon cancer bearing mice compared to a combination of water and DICB. This evidence concerns the gene PDCD1 and malignant colon neoplasm.