So we have a disaccharide component that contains our amino sugar derivative and this is basically repeated many, many times. And then we connect this to our proteoglycan and that is our proteogly glycos aminoglycan molecule. Now, what exactly is the purpose of these proteoglycans attached to our glycos aminoglycan? Well, the purpose is to give our tissue pliability, to give our tissue the ability to basically bend. So it makes our tissue flexible. And one common example is Carthage.