Peng et al. (Peng et al. 2022) successfully identified EP4 as a specific target for PCa immunotherapy by scRNA-seq technology to prove that the novel EP4 antagonist (YY001) enhances the proliferation and anti-cancer function of T cells, inhibiting differentiation and maturation of myeloid cells enhances synergistic effects of anti-PD-1 antibodies. This evidence concerns the gene PTGER4 and cancer.