[1] Univ Hosp Gasthuisberg, Resp Oncol Unit, Louvain, Belgium
[2] Univ Calif Los Angeles, Los Angeles, CA 90024 USA
[3] Univ Penn, Philadelphia, PA 19104 USA
[4] Wilhelminenspital Stadt Wien, Vienna, Austria
[5] Med Univ Vienna, Dept Med 1, Vienna, Austria
[6] Amgen Inc, Thousand Oaks, CA 91320 USA
[7] Duke Univ, Med Ctr, Durham, NC 27706 USA