CD44 and nasopharyngeal carcinoma: Importantly, we found that serglycin induced CD44 expression to potentiate the cells' self-renewal capacity by activating the MAPK/β-catenin pathway (Figures 4 and 5).The Wnt/β-catenin is a crucial CSC signaling pathway and interestingly, NPC CSC-like S18 cells with high-metastic potential expresses nondetectable Wnt (data not shown), which suggests that autocrine ECM serglycin, a CD44 ligand, may be function as Wnt to activate β-catenin pathway in NPC CSC-like S18 cells.