Tumor-derived PGD2 and the natural cytotoxicity receptor 3 (NCR3) ligand B7H6, respectively react with CRTH2 and NCR NKp30 expressed on ILC2s (83), inducing ILC2s, to activate M-MDSC by secreting IL-13 which exhibits the immunosuppressive functions mentioned above (4, 37). Here, IL13 is linked to neoplasm.