[1] Purdue Univ, Dept Biol Sci, W Lafayette, IN 47907 USA
[2] Purdue Univ, Dept Chem, W Lafayette, IN 47907 USA
[3] Purdue Univ, Purdue Ctr Canc Res, W Lafayette, IN 47907 USA
[4] Harvard Med Sch, Boston Childrens Hosp, Stem Cell Program, Boston, MA 02115 USA
[5] Ohio State Univ, Dept Chem & Biochem, Columbus, OH 43202 USA