Biometric Research Branch, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, MD 20892, USA. jshih@mail.nih.gov <jshih@mail.nih.gov>|Biometric Research Branch, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, MD 20892, USA. jshih@mail.nih.gov <jshih@mail.nih.gov>|Biometric Research Branch, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, MD 20892, USA. jshih@mail.nih.gov <jshih@mail.nih.gov>|Biometric Research Branch, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, MD 20892, USA. jshih@mail.nih.gov <jshih@mail.nih.gov>|Biometric Research Branch, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, MD 20892, USA. jshih@mail.nih.gov <jshih@mail.nih.gov>|Biometric Research Branch, Division of Cancer Treatment and Diagnosis, National Cancer Institute, Bethesda, MD 20892, USA. jshih@mail.nih.gov <jshih@mail.nih.gov>