CD44 and ALDH activity are the most common markers of CSCs in OSCC [24, 35]; CD29 is a β1-integrin involved in invasion and metastasis that has been used as a CSC marker for different cancers [36]; and CD56 (N-CAM), which we describe here for the first time in oral cancer, has been correlated with invasion and distant metastasis in many cancers [37-39]. This evidence concerns the gene CD44 and cancer.