T-cell immunoglobin mucin-3 (Tim-3, also known as hepatitis A virus cellular receptor 2), an inhibitory checkpoint receptor, is highly expressed by leukemic cells in several types of AML and high-risk MDS while not present on normal hematopoietic stem cells (HSCs), and its levels are associated with upregulation of proliferation and antiapoptotic genes mostly through galectin-9-mediated Tim-3 activation (Asayama T et al., 2017; Gonçalves Silva I et al., 2017; Kursunel and Esendagli, 2017). This evidence concerns the gene HAVCR2 and myelodysplastic syndrome.