The NAT gene nomenclature committee has curated, annotated, and assigned function to NAT2 star alleles since 1997. In March 2024, NAT2 nomenclature was transferred to PharmVar with some major changes. Most notably, the creation of NAT2*1 as the reference allele in accordance with the reference genome GRCh38. NAT2*4, the former reference allele, is defined by the presence of the SNV c.803G>A. Historically, acetylation function was assigned to NAT2 * alleles as either "rapid" or "slow". Under the CPIC allele function terminology, rapid acetylation alleles are categorized as "Increased Function" and slow acetylation alleles are categorized as "Decreased Function". More information can be found at the NAT gene nomenclature committee website, including legacy allele nomenclature and functional assignments (see links below). Additionally, see the PharmVar NAT2 Read Me document (link below)