Interestingly, a history of diabetes and hyperglycemia was also found to result in severe outcomes with patients infected with SARS (Yang et al., 2006); thus, a proposed mechanism for hyperglycemia in SARS involved the hyperglycemia-induced glycosylation of ACE2 and the viral spike protein, potentially modulating the binding ability of the virus to the receptor. Here, ACE2 is linked to diabetes mellitus.