Figure. Concentration-dependent activation of CYSLTR1 by LTD4. Reporter cells were transfected with either the expression plasmid for cys­teinyl leuko­triene receptor 1 (CYSLTR1) or the mock plasmid and treated with various concentrations of leuko­triene D4 (LTD4). 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 7.9 nM.