For hearing loss, mutations in the GJB2 gene encoding Cx26, one of 21 distinct Cx genes in humans, account for as much as 50% of severe-to-profound inherited deafness cases across diverse ethnic populations (Angeli et al., 2012; Apps et al., 2007; Chan et al., 2010; Duman and Tekin, 2012). The gene discussed is GJB2; the disease is deafness.