FKBP6 is part of the immunophilin protein family, and is involved in immunoregulation and basic cellular functions involving protein folding and trafficking. FKBP6 is widely expressed in all tissues, FKBP6 is present at utmost levels in testis, liver, kidney, skeletal muscle and heart. Deletion of FKBP6 contributes to hypercalcemia and growth delay in Williams-Beuren syndrome.