CP and leukemia: Furthermore, either 17-AAG or CP has the capacity to suppress progenitors by CFU assay; however, only CP is able to inhibit leukemia stem cells significantly by LTC-IC assay, which implicates the combinational treatment is better than the single therapy and the former may suppress human leukemia cells in different differentiation states, including differentiated mature cells, progenitors, and LSCs (Figure 7D).