In diabetic patients infected with COVID-19, exercise may prevent the worsening of immune dysregulation and lung damage by restoring the proliferation and viability of T cells, macrophages, NK cells, and B cells and reducing the accumulation of ROS, TNF-α, serum ferritin, and C-reactive protein [80,99], thus improving patient outcomes and speeding recovery. This evidence concerns the gene TNF and COVID-19.