CD8A and cancer: There is evidence that CD8+ T cell infiltration below 2.2% predicts a fourfold higher risk of disease progression after cancer surgery (hazard ratio (HR) = 3.84, p < 0.01), but the proportion of CD8+ T cells does not correlate with other clinical data, suggesting that the mechanisms that trigger differences in T cell heterogeneity and kinetics are unclear (5, 6).