human chondrocytes (C28/I2 cells), transfected with empty vector (lane 1, 3) or ACVRL1(lane 2, 4). RIPA lysis buffer, 20 ug/lane of protein, primary antibody dilution 1:1000, blocking solution is 5% milk in TBST (lane 1 and 2), 5% BSA in TBST (lane 3 and 4). Data courtesy of Kenneth Finnson, Montreal General Hospital.