[1] NCI, Tumor Immunol & Biol Lab, Bethesda, MD 20892 USA
[2] NCI, Med Oncol Branch, Bethesda, MD 20892 USA
[3] NCI, Bethesda, MD 20892 USA
[4] NCI, Biostat & Data Management Sect, Bethesda, MD 20892 USA
[5] NCI, Tumor Immunol & Biol Lab, NIH, Bethesda, MD 20892 USA