ABSTRACT
CD44 is a cell-surface glycoprotein which binds hyaluronic acid (HA) to mediate cell-cell and cell-matrix interactions, cell migration and tumor growth and progression. CD44 also binds other molecules including osteopontin, collagens, integrins and matrix metalloproteinases (MMPs) and heterodimerizes with c-Met and growth factor receptors including fi broblast growth factor receptor (FGFR). Because all of these interactions can occur within the stem cell niche, it is plausible that CD44 would be critical for mediating stem cell behavior.
