CD44 and neoplasm: Several studies strongly indicate that early tumor relapse and progression is functionally linked to the enrichment of a sub-fraction of cancer cells termed BTICs that undergo EMT-mediated cancer plasticity and typically exhibit a basal-like CD44+/CD24- and/or ALDH1high phenotype with critical cancer stem-like features such as high self-renewal capacity and intrinsic resistance to chemotherapy [50].