Mechanistically, MDSC-mediated inhibition of anti-tumour immunity occurs through a myriad of pathways including expression of arginase 1 (Arg1), inducible nitric oxide synthase (iNOS) and reactive oxygen species (ROS), and secretion of immunosuppressive cytokines such as interleukin 10 (IL-10). This evidence concerns the gene ARG1 and neoplasm.