Not all previously defined star alleles have been transferred: In the past, it has not always been clear how a NAT2 haplotype was determined. Many have been inferred via computational phase analysis and were not verified experimentally. In the case of haplotypes where the available evidence from the literature was deemed insufficient to support confident allele definition, those haplotypes were not transferred to PharmVar, but they will remain posted on the original Database of Arylamine N-Acetyltransferases (NATs).