Mice with targeted deletion of Cx46 or Cx50 develop cataracts.5,6 Many non-functional Cx46 and Cx50 mutants have been linked to human congenital cataracts (reviewed by Beyer et al., Berthoud and Ngezahayo).7,8 We have been using mouse models that mimic some of these mutations to gain insight into how they lead to cataracts. The gene discussed is GJA8; the disease is cataract.