Active Motif's Zebularine is a DNA methyltransferase inhibitor which binds covalently to methyltransferases. Zebularine re-activates silenced E-cadherin expression in EBV-harboring Burkitt's lymphoma Akata cells. It delays tumor growth and induces apoptosis in a genetically engineered mouse model of breast cancer. Zebularine also potentiates differentiation of mesenchymal stem cells into cardiomyocytes, and it inhibits cytidine deaminase (Ki ~ 2 uM)(ref 5). Zebularine is active in vivo.