How the internal liver clock orchestrates daily fat secretion

Every day, the liver packages fat and releases it into the bloodstream to fuel the body, supplying energy to the heart, muscles, and other organs during the active hours of the day. The liver does not release fat into the bloodstream at random. Like much of human physiology, this daily export of fat follows a precise rhythm, timed to the body's internal clock. But what molecular signal tells the liver when to act?