MK-0159 is an orally active, potent and selective CD38 inhibitor, with IC50 values of 22, 3, and 70 nM for human, mouse and rat CD38, respectively. MK-0159 also shows good microsomal stability for human and rodent liver microsomes. MK-0159 increases NAD+ (nicotinamide adenine dinucleotide) and reduces ADPR (adenosine diphosphate ribose) in whole blood and heart[1].