SCN9A and hereditary sensory and autonomic neuropathy: As opioid-dependent analgesia seems to account for the vast majority of the CIP phenotype, intriguingly implying a life-long endogenous opioid action with no tolerance [42], a combination of a specific Nav1.7 antagonist and low doses of opioids or enkephalinase blockers should recapitulate CIP if this mechanism is correct.