Connexin-32 (Cx32), also known as Gap junction beta 1 protein (GJB1), belongs to the connexin family. Connexins are membrane-spanning proteins that assemble to form gap junction channels that facilitate the transfer of ions and small molecules between cells. Connexin-32 is the major gap junction protein of liver, and the expression is also found in brain and other organs. It is involved in tumorigenesis and liver regeneration. Connexin-32 plays an important role in peripheral nerve. Defects in Connexin-32 are the cause of Charcot-Marie-Tooth disease X-linked type 1 (CMTX1), an inherited peripheral neuropathy. (PMID: 8266101; 8613761; 8608591; 19265674)