CD38 and acute myeloid leukemia: Many scientists are interested in this area and have found appropriate biological markers for LSC population in AML, including CD34+CD38− cells [10, 11], CD34+lin− cells [12], CD34+Thy1+CD38low cells [13], CD34+CD117+ cells [14], CD34+CD38−CD123+ cells [15–17], CD34+CD38−CD123+CD33+ cells [18], CD34+CD38−C-type lectin-like molecule-1 (CLL-1)+ cells [19], CD34+CD38−CD96+ cells [20], CD34+CD38−CD45−/low cells [21], CD34/CD123/CD25/CD99+ [5], etc. The CD34+CD38− progenitor cells express varying levels of the target receptors, CD33, CD133, and c-kit (CD117) [22].