Figure. Concentration-dependent activation of CCR9 by CCL25. Reporter cells were transfected with either the expression plasmid for C-C motif chemo­kine receptor 9 (CCR9) or the mock plasmid and treated with various concentrations of C-C motif chemo­kine ligand 25 (CCL25). 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.