Toll-like receptor–evoked ATP release requires activation of PLC, PKC, and an increase in intracellular Ca²⁺. Sample (A-C) and average (D) ATP release stimulated by 10 μg mL⁻¹ Pam₃CSK₄, showing the effect of the PLC inhibitor U73122 (10μM; 10 minutes), intracellular loading with the Ca²⁺ chelator BAPTA (15μM BAPTA-AM) or the PKC inhibitor GF109203X (20μM; 10 minutes; GF).