PDCD1 and neuroendocrine carcinoma: It was also notable that PD-1 expression was significantly higher in ATC compared to NEC (PD-1+ hotspot score: 487 ± 144 cells/mm2 vs. 14 ± 7 cells/mm2, p = 0.0020; PD-1+ average score: 199 ± 60 cells/mm2 vs. 3 ± 1 cells/mm2, p = 0.0021).