TICs are functionally divided into two categories: 1) tumor cell growth inhibition including CD8+ T, Th1 CD4+ T, Th9 CD4+ T, plasma, memory B, NK cells, and DCs; 2) tumor cell growth or immune escape stimulation including Treg, Breg, macrophage M2, and myeloid-derived suppressor cells, (MDSCs) (Kuang et al., 2009; Brandau et al., 2011; Shi et al., 2013; Kim and Cantor, 2014; Liu and Cao, 2016; Mao et al., 2017; Rivera Vargas et al., 2017; Kobayashi et al., 2019; Xie et al., 2021). This evidence concerns the gene CD8A and neoplasm.