CD24 and neoplasm: EMT-mediated cancer cell plasticity also promotes the enrichment of cancer cells with a CD44<sup>high</sup>/CD24<sup>low</sup> and/or ALDH<sup>high</sup> cancer stem-like phenotype [cancer stem cells (CSCs)], characterized by an increased capacity for tumor self-renewal, intrinsic drug resistance, immune evasion and metastasis.