After correlation adjustments by purity, the findings demonstrated that a positive correlation exists between the galectin-9 mRNA expression level and infiltrating levels of CD4 + T cells (R = 0.17, p = 4.79e-03), CD8 + T cells (R = 0.225, p = 1.63e-04), DCs (R = 0.324, p = 3.90e-08) and NK cells (R = 0.324, p = 3.90e-08) in colon cancer, although no statistically significant difference was found in rectal cancer. Here, CD8A is linked to rectal cancer.