[1] NCI, NIH, Bethesda, MD 20892 USA
[2] Guangzhou Med Univ, Guangzhou, Guangdong, Peoples R China
[3] Univ Texas Hlth Sci Ctr San Antonio, San Antonio, TX 78229 USA
[4] Keio Univ, Sch Med, Tokyo, Japan
[5] Georgetown Univ, Lombardi Comprehens Canc Ctr, Washington, DC USA