Potency of recombinant GDF8 and GDF11 from different sources. Luciferase reporter gene assay ((CAGA)12 promoter) following titration of GDF8 (blue) and GDF11 (orange) ligands in HEK293 cells. Luciferase activity was assessed 18–24 h post ligand treatment. The calculated EC50 value for each ligand source using non-linear regression with variable slope is shown in the table below the graph. Data information: Data are presented as percent GDF11 activation after background subtraction (0 nM ligand concentration). Each point is the mean ± SEM of three to four independent experiments. Ligand sources are indicated in the graph. (TIF 750 kb
