TSC1 and Hypercholesterolemia: Here, using two genetically engineered mouse models, we show that osteocytes/osteoblasts produce and secrete SAA3 due to the loss of TSC1 and reduces CYP7A1 expression in hepatocytes through TLR4‐c‐Jun signaling axis, thus impeding hepatic cholesterol catabolism and resulting in hypercholesterolaemia.