PTGS2 and neoplasm: Researches have proved that the content of prostaglandin-endoperoxide synthase 2 in tumor cells undergoing ferroptosis is abnormally increased, resulting in the production of the immunosuppressive factor prostaglandin E2, thereby inhibiting the tumor immune function of traditional type 1 dendritic cells, natural killer cells, and cytotoxic T cells (Zhao et al., 2022).