CD4 and neoplasm: We observed a decreased proportion of immunosuppressive cells (MDSCs and Tregs) and an increased proportion of immunoreactive cells (NKs, NKTs, effector CD4+ T cells, and IFNγ‐producing CD4+ and CD8+ T cells) in the ascites of Tnfrsf14KD‐ID8 tumor‐bearing mice, indicating a robust antitumor effect of targeting HVEM on murine OvCa.