A high fasting blood glucose in patients with COVID-19 correlated to a worse COVID-19 prognosis and higher mortality [71]. In type 1 DM (T1DM), macrophages releasing TNF-α and IL-1 trigger beta-islet cell inflammation [72], substantiated by abundant lymphocytes and neutrophils from the surrounding pancreatic exocrine part [73], while in T2DM, obesity, a known risk factor for COVID-19, is a strong determinator of reduced insulin sensitivity [74]. This evidence concerns the gene TNF and COVID-19.