An inhibitor of cancer cell stemness; reduces growth in a panel of cancer cells enriched for high stemness (IC50s = 0.291-1.249 μM); decreases protein and gene expression of various self-renewal and pro-survival markers in FaDu HNSCC cells; inhibits tumor growth in a PaCa-2 mouse xenograft model and prevents tumor regrowth after cessation of treatment (20 mg/kg per day); blocks formation of spleen and liver metastases in an HT29 ISMS model; reduces tumor volume in PC3 and 22RV1 prostate cancer mouse xenograft models (40 mg/kg)