M1 macrophages from cancer patients are characterized by high levels of reactive oxygen species (ROS) and release higher tumor necrosis factor-alpha (TNF-α) and express more interleukin 1 beta (IL-1β) [21,25,26], while M2 macrophages produce TGF-β, vascular endothelial growth factors α (VEGF-α), and metalloproteinases (MMPs) [21,25,26] (Figure 1). The gene discussed is TNF; the disease is cancer.