However, new research indicates that uridine can serve as an alternative energy substrate under glucose-deficient conditions (e.g., supporting glycolysis via UPP1-mediated ribose catabolism), and in specific pathological states (such as tumor metabolic reprogramming), it may pose a pro-proliferative risk, suggesting that its safety boundaries need re-evaluation [29,30]. This evidence concerns the gene UPP1 and neoplasm.