Receptor subtype 1 Effector Transmitter Receptor subtype 2 Effector 信号网络 system Receptor subtype 3 Effector system Z signaling network ) (a) Transmitter A A receptor 串话( cross-tak)ne B receptor Effector system Transmitter C C recepto Transmitter A receptor Effector 1 Effector 2 A2 recepto Effector 3 Effector 4 Transmitter B B receptor Effector 5信号网络 （signaling network ） 串话（cross－talk）