GJB2 and hearing loss disorder: The importance of gap junctional communication for auditory function has been highlighted by the discoveries that mutations in GJB2 (coding for CX26), GJB6 (CX30) and GJB3 (CX31) may all cause hereditary hearing loss (Rabionet et al. 2002; Lee and White 2009; Xu and Nicholson 2013).