Distal cholesterol biosynthesis, structure of chemical probe SH42, and selectivity assessment. (A) Structure and action of SH42; the red circle emphasizes desmosterol, accumulating due to blockage of DHCR24. 7-DHCR; 7-dehydrocholesterol reductase; FF-MAS, follicular fluid meiosis-activating sterol. (B) LXR target gene activation (qPCR) with (inactive cholesterol biosynthesis) and without (active cholesterol biosynthesis) FCS. ctrl, control. (C) LXR target gene regulation under cotreatment with atorvastatin. For all experiments, results are expressed as mean ± SEM (n = 5). *P < 0.05, **P < 0.01; nonparametric Student’s t test (Mann–Whitney) comparing each group separately with the control group (no treatment).