ACE2 and xerostomia: Data suggest the main risk factors for the onset of oral candidiasis in COVID-19 patients are attributable to direct and indirect effects of the SARS-CoV2 (immunity dysregulation and viral cytopathic effects on ductal epithelial cells the salivary glands [40] expressing high levels of ACE2 [67], responsible for xerostomia) and drugs, essential to treat COVID-19 [40], mainly long-term antibiotics and steroids, which alter the oral microbiota and suppress the immune surveillance, thus favoring opportunistic fungal infections.