Introduction BMP2 is known to activate ER stress signaling molecules, including XBP1S and ATF6.We previously reported that BMP2 induces mild ER stress in chondrocyte differentiation,then XBP1S enhances and controlled growth plate chondrocyte hypertrophy and differentiation.However, whether ATF6 can influence the chondrogenesis has not yet been elucidated;especially, the molecular mechanism underlying these processes remains unexplored.