CD44 and acute myeloid leukemia: Furthermore, we investigated CD44 release in addition to the ECM signature proteins because it can bind to a wide range of extracellular matrix molecules [36,37,38,39,40,41,42,43], it seems to be an important normal stem cell regulator in the endothelial niche [43] and it is involved in interactions between AML cells and AML-supporting endothelial cells [42].