SCN11A and peripheral neuropathy: The discovery of rare mutations in the gene encoding for NaV1.9 in individuals suffering from either a complete loss of pain perception, painful peripheral neuropathy or episodic pain syndromes highlighted NaV1.9 as a potential target to treat pain (Leipold et al., 2013; Zhang et al., 2013; Huang et al., 2014, 2017; Woods et al., 2014; Han et al., 2015).