To understand the PD-1–PD-L1-based tumor–stroma-immune (TSI) crosstalk within the host’s TME in EC in the context of tumor cells and tumor-derived primary CAFs, we studied the compartmental pattern of PD-L1 PD-L2 (Programmed Death-2 ligand), and PD-1 expression in EC tissues and matched tumor-adjacent normal tissues. The gene discussed is CD274; the disease is neoplasm.