PTGS2 and cancer: Additionally, PGE2can foster immunosuppression and treatment resistance within the tumor microenvironment by suppressing NK cell function and inducing the expression of MDSCs and cancer stem cell (CSC) phenotypes (Wang and Dubois, 2010; Holt et al., 2012; Ching et al., 2020; Mao et al., 2014); COX-2 can facilitate the progression of tumor cells by promoting the transformation of arachidonic acid into PGE2, while suppressing anti-cancer immunity (Zelenay et al., 2015; Lira et al., 2024; Li et al., 2020).