Programmed cell death protein 1/programmed death ligand 1 but not HER2 is a potential therapeutic target in gastric neuroendocrine carcinoma.

HER2 is unlikely to be an effective target in gastric NEC owing to the lack of HER2 expression, whereas the PD-1/PD-L1 pathway is a potential therapeutic target for gastric NEC because of the relatively high prevalence of a PD-L1 CPS of ≥ 1 in this subtype.