Figure. Concentration-dependent activation of GPR55 by LPI. Reporter cells were transfected with either the expression plasmid for G protein-coupled receptor 55 (GPR55) or the mock plasmid and treated with various concentrations of lyso­phos­pha­tidyl­in­o­si­tol (LPI). 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 1.2 µM.