CD8A and colorectal adenocarcinoma: As shown in Table 2, according to the best cut-off value, the samples are grouped; CD8+ T quantity in colorectal adenocarcinoma tissue ≤ 7.2 (cells/HPF) is defined as the low-invasive group, the CD8+ T amount of 7.2 (cells/HPF) was defined as the high infiltration group.