CD8A and neoplasm: During MC38 tumour outgrowth, tumour infiltration by CD8+ T cells markedly increased relative to CD4+ T cells (decreasing CD4+/CD8+ ratio, Figure 5A), with the proportion of CD8+ effectors (TEFF) increasing relative to regulatory CD4+ T cells (TREG; decreasing CD4+FoxP3+/CD8+T-bet+ ratio, Figure 5B).