CD68 and acute myeloid leukemia: During treatment with RG7356, we observed a trend for increase of macrophages (CD68+) and decrease of stem cell-like AML blasts (CD34+) in BM biopsies (Figure 3), in agreement with preclinical data that suggested that the mechanism of action of RG7356 involves active macrophage recruitment and subsequent phagocytic activity against tumor cells (Roche internal data).