CD8A and colorectal carcinoma: Additionally, 22 immune cell characteristics were identified as potential protective factors against CRC, such as CD8 on Central Memory CD8+ T cell, CD20 on IgD- CD27- B cell, CD25 on activated CD4 regulatory T cell, and other immune cell traits, with CD25 on activated CD4 regulatory T cell demonstrating the strongest protective effect (OR = 0.865, 95% CI [0.798, 0.938], P < 0.001) (Figure 5).