CD44 and cancer: Moreover, a recombinant humanized Mab, RG7356, that selectively recognizes the HA-binding region of all CD44 isoforms, demonstrated promising results in pre-clinical studies by selectively killing leukemic B cells without affecting the viability of normal B cells in a chronic lymphocytic leukemia (CML) model (232), indicating a potential for Mabs for cancer treatment in clinic.