NOS2 and gastric cancer: In the peripheral blood of gastric cancer patients, the increased mRNA expression levels of arginase 1 (ARG1) and inducible nitric oxide synthase (iNOS), which represent immunosuppressive factors, are also correlated with the increased expression of the ILC2-related markers RORα, T1/ST2, IL-17RB, CRTH2, ICOS, CD45, and the signature cytokines IL-13 and IL-5 (62).