Connexin 33 is a protein that forms gap junctions, which are channels that allow communication between adjacent cells. It is part of the connexin family, which consists of various proteins that facilitate the transfer of ions and small molecules, playing a crucial role in cellular signaling and maintaining tissue homeostasis. This protein is primarily expressed in the nervous system and inner ear, where it contributes to the function of neurons and hair cells. Mutations or dysfunctions in connexin proteins, including connexin 33, can lead to various health issues, such as hearing loss or neurological disorders.