Mesenchymal stem cells (MSCs) transfected by the Id1 promoter reporter construct, cholesterol myristate increases the activity of Id1 promoter. Cholesterol myristate inhibits the apoptosis of MSCs induced by serum-free. Cholesterol myristate increases the expression of Id1 and its target gene bcl-x/l in MSCs treated with serum-free. Moreover, noggin, a BMP antagonist, reduces the anti-apoptotic effects of cholesterol myristate. Cholesterol myristate inhibits the apoptosis of PC12 cells induced in serum-free condition. Cholesterol myristate significantly increases the expression of BMP4, BMPRIA, p-Smad1/5/8, Id1 and its antiapoptotic target gene Bcl-xL in PC12 cells treated in serum-free condition.