Representative signal pathways of CCC.AC adenylate cyclase, cAMP cyclic adenosine monophosphate, cGMP cyclic guanosine monophosphate, CO carbon monoxide, DAG diacylglycerol, ERK extracellular regulated protein kinases, GC guanylate cyclase, GDP guanosine-5'-diphosphate, GPCR G-protein-coupled receptor, GTP guanosine triphosphate, IP3 inositol trisphosphate, IP3R inositol trisphosphate receptor, MAPK mitogen-activated protein kinase, MEK mitogen-activated extracellular signal-regulated kinase, NO nitric oxide, Pi PIP2 phosphatidylinositol-4,5-bisphosphate, PKA protein kinase A, PKC protein kinase C, PKG protein kinase G, PLC phospholipase C