HAMP and hyperinsulinemic hypoglycemia, familial, 4: It was speculated there was a similar structure between the cytoplasmic tail of SARS-CoV-2-spiked glycoprotein and hepcidin protein, so SARS-CoV-2 directly enhances the levels of tissue and circulating ferritin, induces deficiency of hemoglobin and serum iron, and suppresses hepatic hepcidin synthesis [35].