Binding of GTX65631-pro IL2 (Superkine) human Fc fusion protein to IL-2Rβ (human) is increased >10 fold compared to IL-2 human Fc fusion protein. Method: IL-2Rβ (human) protein was coated on an ELISA plate at 1μg/ml. After blocking and washing steps, indicated concentrations of GTX65631-pro IL-2 Superkine (Fc) or IL-2 (Fc) protein were added. Following incubation for 1 h at RT, the binding was detected using an anti-human Fc antibody (HRP).