CD274 and neoplasm: The aging colon often exhibits an increased infiltration of myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs), particularly M2-polarized macrophages, which actively suppress anti-tumor immune responses and promote tumor growth, angiogenesis, and metastasis through various mechanisms, including the secretion of immunosuppressive cytokines (IL-10, TGF-β) and the expression of immune checkpoint molecules (PD-L1) [111].