The new reference allele is now catalogued as NAT2*1: The sequence of NG_012246.1 RefSeq corresponds to the allele that was formerly described as NAT2*12A. Its renaming as NAT2*1.001 facilitates the application of PharmVar rules to NAT2 allelic nomenclature, while it also enables the use of NAT2*1 name to describe the reference allele, in line with the star allele nomenclature of other pharmacogenes. To avoid confusion during the transition from the legacy to the new nomenclature, *12 is now retired. Having a NAT2*1 allele grouping in place also facilitates NGS analyses using GRCh38 as a reference.