Figure 1. Cholesterol biosynthesis pathway.
Simplified schematic of cholesterol biosynthesis starting from Acetyl-CoA. After 13 enzymatic steps, the intermediate Lanosterol can enter one of two parallel pathways designated Bloch and Kandutsch-Russel pathways, respectively, both of which employ an NADPH-dependent reduction step which can be catalyzed by sterol C14 reductases LBR or TM7SF2 (highlighted in magenta). Adapted, with modifications, from (Sharpe and Brown, 2013). The inset on the upper right depicts distinct subcellular localizations of the human sterol reductases LBR and TM7SF2 localizing to the inner nuclear membrane and ER, respectively.