QPRT and amyotrophic lateral sclerosis: The expression of NADSYN1, NAMPT, PARP8/9/16, PTGS2, NT5C2, BST1, SIRT1/5, and NADK was significantly up-regulated in ALS, whereas QPRT, SLC5A8, NMNAT3, PARP6/14/10, NT5C, ENPP1, and SIRT2 were significantly downregulated.