Sterol regulatory element-binding protein 2

And they come back to the liver and they satisfy the liver's free cholesterol requirement.

And so there is a sterile sensor in the liver called SREBP2, sterile regulatory element binding protein 2.

And it dictates the transcription of HMGCR, which is cholesterol synthesis.

LDL receptor, which is the claw grabber that pulls in the LDL particle from the periphery.

So as is insulin, as is almost everything in biology, there's a sweet spot.

But because the liver is actually getting its sterile requirement from the chylomicrons, which have a ton of cholesterol, over 50,000 molecules of cholesterol per particle sometimes versus only 2,700-ish for an LDL particle, it's satisfying that cholesterol requirement.

And so what it does is it down-regulates the SREBP2, which down-regulates HMG-HCR.

It down-regulates LDL receptor expression.