Our choice for the TM2 orientation is based on the analysis of disease−associated mutants and polymorfisms of Cx32, and the closely related Cx26 (see http://davinci.crg.es/deafness/, http://webh01.ua.ac.be/hhh/, http://www.molgen.ua.ac.be/CMTMutations/ and at NCBI's Online Mendelian Inheritance in Man server http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?CMD=search&DB=omim). This evidence concerns the gene GJB2 and deafness.