In addition to its widespread and complex role in immune cells, TIM-3 has also been identified as a stem cell antigen in myeloid cell leukemias, with expression on the majority of CD34+ CD38- leukemic stem cells (LSCs) and CD34+ CD38+ leukemic progenitors in acute myeloid leukemia (AML), but not on CD34+ CD38- normal hematopoietic stem cells [24, 25]. This evidence concerns the gene CD38 and acute myeloid leukemia.