[1] Univ Calif San Francisco, San Francisco, CA 94143 USA
[2] Cornell Univ, Biochem Mol & Cell Biol Sect, Ithaca, NY 14853 USA
[3] Rutgers State Univ, Waksman Inst, Dept Genet, Piscataway, NJ 08854 USA
[4] Proctor & Gamble Pharmaceut, Hlth Care Res Ctr, Mason, OH 45040 USA