CD33 and myelodysplastic syndrome: In addition to CD123 targeting biotherapeutic agents, CD33 targeting antibodies and BiABs (CD3 × CD33 or CD16 × CD33) also show potential for the treatment of high-risk MDS patients because of the high level expression on both MDS clones and MDSC (Eksioglu et al., 2017); (Gleason et al., 2014).