Therefore, the inhibition of NAD synthesis pathways, e.g., by blocking the rate-limiting enzymes such as nicotinamide phosphoribosyltransferase (NAMPT) in the salvage pathway or nicotinic acid ribosyl transferase (NAPRT) in the Preiss-Handler pathway (Figure 1) is currently being explored as a potential component of cancer therapies [18,65,66]. This evidence concerns the gene NAMPT and cancer.