Compared to the immune microenvironment of SCLC, only neutrophil infiltration was significantly higher in NEC‐GYN (P ≤ 0.0001) (Fig. 3C, Fig. S20); however, HLA‐A and HLA‐B expression were significantly lower in our cohort (Fig. 3D) demonstrating lower antigen presentation capacity. Here, HLA-A is linked to neuroendocrine carcinoma.