NAMPT and viral infectious disease: Furthermore, nicotinamide phosphoribosyltransferase (NAMPT) catalyses biosynthesis of nicotinamide adenine dinucleotide (NAD) from nicotinamide and NAMPT/NAD metabolism is altered in response to both viral infections and tumor growth, indirectly indicating the influence of tumor metabolic status on the progression of a patient’s COVID-19 disease [3].