Connexin refers to a family of proteins that form gap junctions, which are specialized connections between adjacent cells. These proteins allow for the direct transfer of ions and small molecules, facilitating communication and coordination between cells. There are several types of connexins, each with specific functions and tissue distributions. Gap junctions formed by connexins play a crucial role in various physiological processes, including cardiac function, neuronal signaling, and tissue homeostasis. Dysfunction in connexin proteins can lead to various diseases, highlighting their importance in maintaining cellular communication and overall health.