[1] Stanford Univ, Ctr Clin Sci Res, Dept Radiat Oncol, Stanford, CA 94305 USA
[2] Stanford Univ, Programs Epithelial Biol & Canc Biol, Stanford, CA 94305 USA
[3] Duke Med Ctr, Inst Genome Sci & Policy, Dept Mol Genet & Microbiol, Durham, NC 27708 USA