The PD-L1 IHC revealed that high-grade NENs possessed a higher number of PD-L1-positive tumor cells and lymphocytes than low/intermediate-grade NENs (CPS 4.50 (2.88–12.50) vs. 0.50 (0.00–2.50), p < 0.001) (Figure 1D)). This evidence concerns the gene CD274 and neoplasm.