HMGCR and familial hypercholesterolemia: In an animal study on mouse models with dietary IO, an increase in the activity of acyl-CoA cholesterol acyltransferase (ACAT) and a decrease in HMG CoA reductase and 7 α-hydroxylase were observed, and they were both correlated with hypercholesterolemia and unaltered hepatic cholesterol content, indicating that cholesterol’s synthetic and excretory pathways are not affected by IO, while the secretory pathway may be upregulated, resulting in hypercholesterolemia [112].