HSPG2 and neuroblastoma: While calcium release upon stimulation with both BK and CCh is associated with G-protein coupled receptor (GPCR) activation and InsP3 generation, in spite of sharing the same calcium pools, such differential effects between BK- and CCh-evoked calcium responses have been previously described in airway smooth muscle and neuroblastoma cells and proposed to be regulated by differences in the specific PLC involvement and the expression of muscarinic receptors [45, 46].