TNF and Hyperglycemia: Exposure of cultured human pancreatic islets to serum obtained from humans hospitalized for COVID-19 with new-onset hyperglycemia or who had recovered from COVID-19 led to islet apoptosis and a dramatic reduction in insulin secretion, which were mediated by proinflammatory cytokines including IL-1β, IL-6, IL-13, IP-10, and TNF-α (305).