Keywords: HMG-CoA R; 3-hydroxy-3-methylglutaryl-coenzyme A reductase; 3α-diol; 5alpha-androstane-3alpha,17beta-diol; 3β-diol; 5alpha-androstane-3beta,17beta-diol; 7α-OH; 7α-hydroxycholesterol; 7β-OH; 7β-hydroxycholesterol; 7-keto; 7-ketocholesterol; 24(S)-OH;