The channels form by the docking of two hemichannels, which are hexameric oligomers of connexin subunits.7 Connexin 46 (Cx46) (α3 connexin) and connexin 50 (Cx50) (α8 connexin), encoded by the Gja3 and Gja8 genes, respectively, are the major subunits for gap junctions in mouse lens fibers.5 Connexins are essential for lens development and homeostasis as demonstrated by the various adverse effects, such as cataracts and growth defects, that occur in animals and humans due to Cx46/Cx50 knockouts (KO) and mutations.8, , , , –13 In particular, only Cx50 is critical for lens size. Here, GJA3 is linked to cataract.