NAMPT and congenital secretory chloride diarrhea 1: On the other hand, in CLDS2, when NAMPT is downregulated, the supply of NAD+ is not expected to be sufficient.It has been reported that when NAD+ is decreased, the activity ofsirtuin, a NAD-consuming enzyme, decreases, leading to mitochondrialdysfunction.37 NADP+ has also been shownto be an important metabolic product that characterizes CLD throughmultiomics analysis using mixOmics (Figure S3B).