KCNH1 and neuroblastoma: For example, maturation of neuroblastoma cells derived from neural crest cells can be characterized by an ordered expression of currents: a human eag-related K+ channel current and a delayed rectifier K+ channel current are detected at early stages and are and replaced at later stages by a tetrodotoxin-sensitive Na+ channel current and an inward rectifier K+ channel current [21], [51], [52].