To delineate the potential immune constituents within the tumor microenvironment influenced by TNFRSF14/HVEM, we investigated both lymphoid cells (CD3+ T cells, CD4+ T cells, CD8+ T cells, natural killer T cells [NKTs], natural killer cells [NKs], and B cells) and myeloid cells (myeloid‐derived suppressor cells [MDSCs], macrophages, and dendritic cells) in the ascites and spleens of both Ctrl‐ID8 tumor‐bearing mice and Tnfrsf14KD‐ID8 tumor‐bearing mice. Here, TNFRSF14 is linked to neoplasm.