Hydroxyacid oxidase 1 (HAO-1), a member of the FMN-dependent alpha-hydroxy acid dehydrogenase family, is also known as glycolate oxidase (GOX), which contains 1 FMN hydroxy acid dehydrogenase domain. HAO-1 Has 2-hydroxyacid oxidase activity. Most active on the 2-carbon substrate glycolate, but is also active on 2-hydroxy fatty acids, with high activity towards 2-hydroxy palmitate and 2-hydroxy octanoate.