CD4 and neoplasm: This metabolic reprogramming fosters the expansion of immunosuppressive cells, such as regulatory T cells (Tregs), myeloid-derived suppressor cells (MDSCs), and tumor-associated macrophages (TAMs), while blunting the activity of anti-tumoral immune cells, including dendritic cells (DCs), CD4-positive T helper cells (Th1), CD8-positive T cells (CD8+ T), natural killer (NK) cells, and M1 macrophages (M1), helping the tumor to escape from immunosurveillance [5,6].