Importantly, the activation of Na+ channels by P-CTX-1B has been shown to lead to direct mobilisation of Ca2+ from internal stores in neuroblastoma cells and rat myotubes [11], [12] and to an indirect activation of the Na+/Ca2+ exchanger in the reversed mode in cholinergic synaptosomes, allowing Ca2+ influx against Na+ efflux [13]. The gene discussed is SLC8A1; the disease is neuroblastoma.