CD8A and rectal cancer: According to TIMER2.0 and enrichment analyses of the rectal cancer-specific genes (upregulated) group, other immune cells such as myeloid-derived suppressor cells, macrophage M1, B cell naïve, common lymphoid progenitor, T cell CD4+ T helper 2, T cell CD4+ (non-regulatory), T cell CD4+ memory resting, B cell, T cell natural killer, T cell CD4+ memory resting, T cell CD4+ naïve, and T cell CD8+ central memory cells play important regulatory roles in the tumor immune microenvironment (Figures 3(c), 3(i), and 6(a)).