Our previous work demonstrated that mice treated intravenously with a prodrug of SpiD3 (SpiD3_AP, 3 days), which has anti-leukemic effects comparable to that of SpiD3, displayed marked clearance of CLL (CD19+/CD5+) cells in the spleen [20] (Figure 5A). Here, CD19 is linked to B-cell chronic lymphocytic leukemia.