CD8A and colorectal carcinoma: When patients were divided into two groups depending on the severity of CRC according to the TNM classification (TNM-I + II vs. TNM-III + IV), a distinctly (and statistically significant) difference was visible only for CD8-IF, and a higher number of CD8 cells was found in less advanced tumors (209.18 ± 18.24 vs. 168.31 ± 13.53; p = 0.043).