CD34 and acute lymphoblastic leukemia: From our literature search, the concept of acquired cancer stemness has not yet been described in hematological malignancies, although a good number of CSC markers for these cancers have been proposed, including CD34+/CD38-/CD90−/interleukin 3 receptor(IL-3R)+/human leukocyte antigen (HLA)-DR/CD117- for acute myeloid leukemia (AML), CD34+/CD10-/CD19-/CD133+ for B-cell precursor acute lymphoblastic leukemia (ALL), and CD34+ for chronic myeloid leukemia (CML) [43, 44].