ACOX2 and peroxisomal disease: Unpublished data from a study of plasma samples from patients with the peroxisomal disorder acyl-CoA oxidase 2 (ACOX2) deficiency (Fig. 1A) where cholestenoic acids, including 25 R- and unusually 25 S-epimers of CA4-7α,12α-diol-3-one build-up, substantiates the identification of the 25 R-epimer of CA4-7α,12α-diol-3-one in the current study eluting at 4.16 and 4.64 min.