P2RX7 agonist-induced ERK1/2 phosphorylation. RAW 264.7 macrophages, untransfected HEK-293 cells, and HEK-293 cells that were transfected with the pIREShyg or pIRES/hP2RX7 expression vectors were stimulated with vehicle (2.5 mM HEPES), 10 μg/mL anisomycin, 250 μM BzATP, or 100 μM forskolin for the indicated times and immunoblotted to detect ERK1/2 phosphorylation. Immunoblotting was performed with the anti-Grb2 antibody as a loading control. The results of the three independent experiments were combined, and BzATP-induced ERK1/2 phosphorylation was graphed (mean±sem).