CD44 and breast cancer: Flow cytometry analysis of the tumor cells stained with anti-human CD44-PE/CD24-FITC indicated that sunitinib treatment in vivo significantly increased the percentage of breast cancer stem cells (CD44+/CD24- or low) in basal like breast cancer (MDA-MB-468) in athymic nude-foxn1 mice (3.6 ± 0.3% vs. 6.4 ± 0.5%; n = 4; P < 0.01) as shown in Figure 5.