NAT1 (N-acetyltransferase 1) is a phase II xenobiotic-metabolizing enzyme located on chromosome 8 that catalyzes both N-acetylation and O-acetylation of aromatic and heterocyclic amine substrates 1. The enzyme plays a dual role in carcinogen metabolism, typically detoxifying compounds through N-acetylation but potentially bioactivating certain carcinogens through O-acetylation 2. NAT1 is widely distributed throughout the body and contains a catalytic triad similar to cysteine proteases 1. The only confirmed endogenous substrate is the folate catabolite p-aminobenzoylglutamate, suggesting a role in folate homeostasis 1. The gene exhibits significant genetic polymorphism with multiple allelic variants showing different functional activities 3. Meta-analyses indicate that NAT1*10 may confer modest protection against bladder cancer 4, while associations with other cancers remain inconsistent 5. Recent research has identified NAT1's involvement in diabetes through modulation of spermidine levels and RIPK1 acetylhypusination 6. The enzyme's genetic variants primarily affect protein stability, with most mutations producing unstable proteins subject to degradation 1. NAT1's role extends beyond xenobiotic metabolism to fundamental cellular processes including folate metabolism and inflammatory pathway regulation.