Although too much cholesterol is bad for your health, some cholesterol is essential. Most of the cholesterol that the human body needs is manufactured in its own cells in a synthesis process consisting of more than 20 steps. New research from the University of New South Wales in Sydney, Australia, to be published in the Journal of Biological Chemistry on Dec. 8, explains how an enzyme responsible for one of these steps acts as a kind of thermostat that responds to and adjusts levels of cholesterol in the cell. This insight could lead to new strategies for combating high cholesterol.