Figure. Concentration-dependent activation of PTGER2 by misoprostol. Reporter cells were transfected with either the expression plasmid for prosta­gland­in E receptor 2 (PTGER2) or the mock plasmid and treated with various concentrations of misoprostol. 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 1.1 µM.