[1] Univ Penn, Sch Med, Leonard & Madlyn Abramson Family Canc Res Inst, Signal Transduct Program, Philadelphia, PA 19104 USA
[2] Univ Penn, Sch Med, Grad Program Immunol, Philadelphia, PA 19104 USA
[3] Hosp Univ Penn, Dept Med, Philadelphia, PA 19104 USA
[4] Univ Penn, Sch Vet Med, Dept Pathobiol, Philadelphia, PA 19104 USA
[5] Univ Penn, Sch Med, Dept Pathol & Lab Med, Philadelphia, PA 19104 USA
[6] Haverford Coll, Dept Biol, Haverford, PA 19041 USA
[7] Univ Iowa, Mol Biol Grad Program, Iowa City, IA 52242 USA
[8] Univ Iowa, Coll Med, Dept Internal Med, Iowa City, IA 52242 USA