Figure. Concentration-dependent activation of CCR7 by CCL21. Reporter cells were transfected with either the expression plasmid for C-C motif chemo­kine receptor 7 (CCR7) or the mock plasmid and treated with various concentrations of C-C motif chemo­kine ligand 21 (CCL21). 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 15 nM.