Sterol 14α-demethylase (CYP51), the most widely distributed member of the P450 superfamily, is the key enzyme in sterol biosynthesis pathway. CYP51 is not only an important model for fundamental P450 structure/function studies, but also an important target protein of cholesterol-lowering agents, antifungal drugs and herbicides. This article reviewed the research advances in CYP51 at various aspects, including sequence characteristics, physiological roles, catalytic properties in vitro, protein structure, structure-function relationships and in...