<prompt> Collagen present in skin isType IType IIType IVType V  <response>: Collagen Collagen is the most abundant protein in the human body, have a triple helical structure At least 28 distinct types of collagen made up of over 30 distinct polypeptide chains have been identified in human tissues The main fibril forming collagens in skin and bone and in cailage, respectively, are types I and II. Ref:- Harper 30e; pg num:- 628 , Lippincott 7e; Pg Num:- 44 