[1] NCI, Biometr Res Branch, Div Canc Treatment & Diag, NIH, Bethesda, MD 20892 USA
[2] NCI, Canc Diag Program, Div Canc Treatment & Diag, NIH, Bethesda, MD 20892 USA
[3] NCI, Canc Treatment & Evaluat Program, Div Canc Treatment & Diag, NIH, Bethesda, MD 20892 USA