1. 1Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, Maryland.
2. 2Cepheid, Sunnyvale, California.
3. 3Department of Oncology, Renmin Hospital of Wuhan University, Wuhan, Hubei, P.R. China.
4. 4Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland.
5. 5Department of Surgery, Johns Hopkins University School of Medicine, Baltimore, Maryland.