NAMPT and Thrombocytopenia: Inhibitors of the nicotinamide phosphoribosyltransferase (NAMPT), an enzyme responsible for the conversion of nicotinamide to nicotinamide mononucleotide, showed efficacy in various preclinical and clinical studies, but their clinical utility has been limited by on-target and dose limiting toxicities such as thrombocytopenia and adverse GI effects.