Cx31, or Connexin 31, is a protein that forms gap junctions, which are channels that allow communication between adjacent cells. It plays a crucial role in maintaining the function of various tissues, including the skin and the inner ear. Mutations in the Cx31 gene can lead to certain health conditions, such as ichthyosis and hearing loss. This protein is part of a larger family known as connexins, which are essential for cell signaling and maintaining homeostasis in tissues. By facilitating the transfer of ions and small molecules, Cx31 helps regulate processes like cell growth and repair, making it vital for overall cellular health.