Biology of collagen.

Recent major advances in our knowledge of the biology of collagen considerably facilitated an understanding of the structure, function and pathology of connective tissues. This short review is designed as an introduction to current concepts and findings in collagen polymorphism, its biosynthesis, degradation, and interaction with the ground substance. Such a discussion will serve as a basis for a review of the current concepts and advances regarding the tissue distribution, and specific functional roles, of the different types of collagen, as well as the disorders of the connective tissue that involve collagen. We hope that this article will serve to grant the reader an opportunity to gain an overview of the developments in the research related to this fascinating protein. It was also our intention to show how much more remains to be learnt about the biology of collagen.