CD44 and acute myeloid leukemia: CD44 is a type I transmembrane protein that serves as adhesion molecule expressed by hematopoietic cells and at a higher level by stromal cells, whereas HCELL is expressed exclusively on healthy and AML hematopoietic cells, including HSC and LSC (Dimitroff et al., 2000; Peterson et al., 2007; Will and Steidl, 2010; Levesque and Winkler, 2016; Gruszka et al., 2019).