May act as a carrier of hyaluronan in serum or as a binding protein between hyaluronan and other matrix protein, including those on cell surfaces in tissues to regulate the localization, synthesis and degradation of hyaluronan which are essential to cells undergoing biological processes. This is the function of Ensembl gene identifier ENSG00000151655 (ITIH2, inter-alpha-trypsin inhibitor heavy chain 2).