SAMHD1 and acute myeloid leukemia: SAMHD1 is widely expressed in a variety of normal cells (Supplementary Fig. 4a), especially in immune cells, such as macrophages, dendritic cells, and lymphocytes, which mediates resistance to infection by HIV and DNA viruses.5,6 In contrast to the results in AML cells, HSP90 inhibitors had little effect on SAMHD1 expression in peripheral blood mononuclear cells (hPBMCs) and granulocytes (hGRAN) from healthy donors (Figs. 4a, b and S4d).