CDX2 and myelodysplastic syndrome: The caudal-related homeobox gene CDX2 is not expressed in normal hematopoietic stem cells (HSCs), but is expressed in ~90% of acute myeloid leukemia (AML) patients1,2, as well as those with high-risk myelodysplastic syndrome (MDS) and advanced chronic myeloid leukemia (CML).