IL4 and neoplasm: ,19 MDSCs primarily exhibit immune suppression and inhibit the activation of various immune cells through the production of inducible nitric oxide synthase and reactive oxygen species.20, 21, 22 Tumor-associated macrophages can be classified into two types: M1-type macrophages that secrete pro-inflammatory factors like tumor necrosis factor-α, interferon-γ, and IL-β, and M2-type macrophages that secrete anti-inflammatory factors such as IL-4, TGF-β, and epithelial growth factors, promoting tumor proliferation and migration.23, 24, 25