Supplementary Fig. 1: Comparison of labeled and unlabeled 7-Dehydrocholesterol.

A) Labeled 7-Dehydrocholesterol after incubation of HL60 cells with AY9944 and 2-13C-acetate. The red lines denote the isotopes +4 to +11 of the two most prominent peaks in the spectrum, used for quantification. B) unlabeled control.