PD-1/CD4 and PD-1/CD8 ratios were significantly higher in NEC than in non-NEC components (PD-1/CD4 intra: p = 0.0127, margin: p = 0.0070; PD-1/CD8 intra: p = 0.0176, margin: p = 0.0484). This evidence concerns the gene CD4 and neuroendocrine carcinoma.