TRANSFERASE, NMPRTASE, NAMPRTASE, VISFATIN, NMN, NICOTINAMIDE D-RIBONUCLEOTIDE, PYROPHOSPHATE, ALTERNATIVE SPLICING, CYTOPLASM, GLYCOSYLTRANSFERASE, PHOSPHOPROTEIN, POLYMORPHISM, PYRIDINE NUCLEOTIDE BIOSYNTHESIS CRYSTAL STRUCTURE OF HUMAN NAMPT COMPLEXED WITH NICOTINAMIDE MONONUCLEOTIDE AND PYROPHOSPHATE 3DHD