ERK and FRS2alpha phosphorylation induced by FGF21 in bKlotho expressing cells. bKlotho expressing cells were serum starved for 16hr and then stimulated with hFGF21-His (competitor), ab108556 (FGF 21-Fc), mCD137-Fc (Fc control) and FGF-b (positive control) for 10 minutes, respectively. Antibodies against pFRS2alpha, pERK1/2 & total ERK1/2 were used for immunoblotting. Lane 1: 1 µg/ml hFGF21-His (competitor) Lane 2: 2.2 µg/ml ab108556 (hFGF21-Fc) Lane 3: 2.2 µg/ml mCD137-Fc Lane 4: 100 ng/µl FGF-b Lane 5: control (non-treated)