Figure. Concentration-dependent activation of GRPR by GRP. Reporter cells were transfected with either the expression plasmid for gas­trin re­leas­ing pep­tide receptor (GRPR) or the mock plasmid and treated with various concentrations of gas­trin-re­leas­ing pep­tide (GRP). 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 1.3 nM.