[1] TEMPLE UNIV,HLTH SCI CTR,SCH MED,DEPT PATHOL,PHILADELPHIA,PA 19140
[2] TEMPLE UNIV,HLTH SCI CTR,SCH MED,FELS RES INST,PHILADELPHIA,PA 19140
[3] UNIV PITTSBURGH,DEPT BIOL SCI,PITTSBURGH,PA 15260
[4] JOHNS HOPKINS UNIV,SCH MED,DEPT MOLEC BIOL & GENET,HOWARD HUGHES MED INST LAB,BALTIMORE,MD 21205