CLCN7 and osteopetrosis: The morpholino downregulation of the CLCN7 zebrafish ortholog (clcn7) leads to Tgf-β-mediated defects in craniofacial cartilage and teeth that mimic some of the symptoms shown by patients with the severe neonatal, infantile, intermediate, or late-onset forms of osteopetrosis (Zhang et al., 2019).