Fibrocystin is a protein primarily found in the kidneys and is encoded by the PKHD1 gene. It plays a crucial role in the development and function of kidney tubules, which are essential for filtering blood and producing urine. Mutations in the PKHD1 gene can lead to polycystic kidney disease, a condition characterized by the formation of fluid-filled cysts in the kidneys. This protein is also involved in cellular signaling and maintaining the structure of kidney cells. Understanding fibrocystin's function is important for developing treatments for kidney diseases, particularly those related to cystic kidney disorders. Research continues to explore its role in kidney health and disease.