CD274 and severe acute respiratory syndrome: In line with these roles, PD-L1-SARS is accompanied by a Th1/Th17-leaning immune contexture (IFN-γ and IL-17 signals; CD8+ infiltration↑, FOXP3+ Tregs↓, M1-type macrophage polarization) and IFN-γ–linked proteomic enrichment.