PROM1 and neoplasm: Quantitative assessment of the stained HT29 xenograft tumor revealed that treatment with metformin alone significantly decreased the proportion of CD44+ cells but not that of CD133+ cells (control group vs. metformin group: CD44+ cells, 19.3% vs. 6.8%, P < 0.001; CD133+ cells, 26.5% vs. 19.5%, P = 0.183), whereas treatment with compound 968 did not significantly decrease the proportion of cells positive for either marker (control group vs. 968 group: CD44+ cells, 19.3% vs. 12.2%, P = 0.152; CD133+ cells, 26.5% vs. 21.2%, P = 0.118).