Figure 1. Scheme representing hepatocyte specific hURI expression leading to DNA damage and liver tumorigensesis.

Mechanistically, we demonstrate that URI inhibits de novo NAD⁺ synthesis through cytoplasmic sequestration of aryl hydrocarbon and estrogen receptors (AhR and ER, respectively), both of them are transcription factors of enzymes implicated in catabolism of tryptophan to NAD⁺ synthesis [5].