SIRT1 expression was significantly decreased in COVID-19 patients, and at the same time negatively correlated with p53 and the concentration of proinflammatory cytokines [107], offering an indirect role for renalase employment as a regulator of NAD+ [19, 24] for SIRT1 upregulation in cases of severe COVID-19 [107]. Here, SIRT1 is linked to COVID-19.