CD274 and neoplasm: We evaluated the abundance (i.e., defined as normalized cell densities = number of marker positive cells/mm2) and localization (total, tumor and stroma area) of the different immune cell subpopulations based on i) the expression of single markers (CD4+ for T-helpers, CD8+ for cytotoxic T-cells, FoxP3+ for T-regulatory cells, CD68+ for macrophages) and ii) the respective co-expression of PD-L1 and PD-1 checkpoint markers on these cells (Fig. 3A, Supplementary Table 3).