CD33 and myelodysplastic syndrome: CD33 is a therapeutic target on MDSCs across different cancer subtypes in human.338 Recently, a fully humanized, Fc-engineered mAb against CD33 known as BI 836858 has been proved to inhibit CD33-mediated signal transduction in myelodysplastic syndrome (MDS) patients.339 The findings indicated that BI 836858 depleted MDSCs through Ab-dependent cell-mediated cytotoxicity (ADCC).