Patients with COVID-19 have a high prevalence of diabetes, and diabetes and blood glucose control are determinants of intensive care unit admission and mortality.1,2 The risk and severity of infection in patients with diabetes and COVID-19 are associated with increased angiotensin-converting enzyme 2 expression, increased furin levels, impaired T-cell function, and increased interleukin (IL)-6,1 which makes it possible for diabetes to promote COVID-19 infection because of increased viral entry into cells and impaired immune response.1 This evidence concerns the gene FURIN and diabetes mellitus.