Collagen VI acts as a cell-binding protein. Trimers composed of three different chains: alpha-1(VI), alpha-2(VI), and alpha-3(VI) or alpha-4(VI) or alpha-5(VI) or alpha-6(VI). In newborn, it is expressed in lung, kidney, brain, intestine, skin, sternum and, at weak level, calvaria. In adult, it is almost absent with some weak expression in ovary and very weak expression in spleen, lung, uterus and brain. Prolines at the third position of the tripeptide repeating unit (G-X-Y) are hydroxylated in some or all of the chains. Belongs to the type VI collagen family.