CD44 and cancer: Increased HA production has been linked to GBM aggressiveness, via enhanced cancer cell proliferation, chemo- and radio-resistance and invasiveness.38,39 This has been attributed to engagement of HA receptors, such as CD44, on tumor cells, and it is likely that the migratory response of GBM cells to HA-rich, astrocyte-deposited ECM is mediated via CD44.