Figure. Concentration-dependent activation of CRHR1 by CRH. Reporter cells were transfected with either the expression plasmid for cortico­tropin re­leas­ing hormone receptor 1 (CRHR1) or the mock plasmid and treated with various concentrations of cortico­tropin re­leas­ing hormone (CRH). Data points shown are the mean ± SEM of an experiment performed in triplicate, and the curve is a fit to Hill equation with an EC50 of 22 nM.