To investigate the factors that may regulate the reactive efficiency of PD-L1 expression, we divided tumors into four tumor microenvironment (TME) types according to the median expression of PD-L1 and CD8A, in which TME III is CD8A-low and PD-L1-high whereas TME IV is CD8A-high and PD-L1-low (Figure 3D). The gene discussed is CD8A; the disease is neoplasm.