Heparan sulfate proteoglycans (HSPGs), including transmembrane (syndecan), glycosylphosphatidylinisotol (GPI)-anchored (glypican), secretory granule-derived (serglycin) and secreted HSPGs (perlecan, agrin and betaglycan), are large heterogeneous molecules that interact with growth factors, chemokines and structural proteins of the ECM to influence cellular differentiation and tumor progression [162–164]. Here, CD44 is linked to neoplasm.