In this T-NEN cohort, we demonstrated that the majority of T-NEN harbored various degrees of CD4+ TILs (86.3%) and CD8+ TILs (84.3%), as well as CD14+ monocyte (94.1%) and CD15+ granulocyte (43.1%) infiltration, thus displaying an “immune-inflamed” landscape and making immunotherapy a rational way to tackle tumor progression in T-NEN. This evidence concerns the gene CD8A and neoplasm.