This observation suggests that NNMTi treatment effectively counters hepatic NNMT activity; overexpression of NNMT (concurrent with nicotinamide supplementation) has been shown to drive fatty liver disease and promote steatosis, inflammation, and fibrosis which are associated with dysregulated NAD/sirtuin pathway- and methionine cycle-linked epigenetic mechanisms21. Here, NNMT is linked to fatty liver disease.