CD44 and central nervous system cancer: Glioma cells possess CD44 as a receptor for interacting with brain matrix hyaluronan (Murai et al., 2004; Yoshida et al., 2012), and secrete hyaluronidases and metalloproteinases to facilitate their migration (Delpech et al., 2002; Junker et al., 2003; Hagemann et al., 2012).