With the exception of small-cell lung cancer (42%; 95% CI: 28–58%) and neuroendocrine tumors (13%; 95% CI: 4–31%; Figure 2), the prevalence of PD-L1 expression (i.e., CPS ≥1) in each of the tumor types evaluated was greater than 50%. This evidence concerns the gene CD274 and neuroendocrine neoplasm.