For example, MDSCs can inhibit lymphocytes by expressing Argininase-1 (Arg-1), inducible nitric oxide synthase (iNOS), reactive oxygen species (ROS), and other substances; induce other tolerant immune cells, such as regulatory T cells(Tregs), regulatory B cells, and tumor-associated macrophages (TAMs); and indirectly inhibit T cells or effector B cells [1]. The gene discussed is ARG1; the disease is neoplasm.