Figure. Concentration-dependent activation of NPY1R by NPY. Reporter cells were transfected with the expression plasmid for neuro­pep­tide Y receptor Y1 (NPY1R) and treated with various concentrations of neuro­pep­tide Y (NPY). 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 840 pM.