XVI collagen is a member of the FACIT collagen family (fibril-associated collagens with interrupted helices). Members of this collagen family are found in association with fibril-forming collagens such as type I and II, and serve to maintain the integrity of the extracellular matrix. High levels of type XVI collagen have been found in fibroblasts and keratinocytes, and in smooth muscle and amnion.The remaining collagens belong to the latter class with a common feature being the presence of imperfections in the gly-Xaa-Xaa repeating pattern. Within the latter class, collagens type IX, XII, and XIV form a subgroup called the FACIT collagens (for 'fibril-associated collagens with interrupted triple helices'). These collagens are associated with type I or II collagen fibrils and play a role in interaction of these fibrils with other matrix components.