Connexins (Cx) include 21 integral membrane proteins belonging to this family and form homomeric or heteromeric hexamers generally termed connexons or hemi-channels. In turn, these hemi-channels further assemble in a head-to-head manner, thus forming gap junction channels. Connexins are ubiquitously expressed and their activity is regulated at the expression level and by post-translational modifications. Due to their important roles, mutations in connexins are linked to a number of diseases such as neurodegenerative disorders, skin diseases and developmental abnormalities.