As shown in Fig. 1 and Additional file 1: Table S1, only 5000 cells of CD44+/CD24-/ cells could form a tumor whereas 1 × 104 CD44-/CD24- or ESA-/CD24+ cells could not, suggesting that CD44+/CD24-and ESA+/CD24- cells have characteristics of cancer stem-like cells. This evidence concerns the gene CD44 and cancer.