He F, Deng X, Wen B, Liu Y, Sun X, Xing L, Minami A, Huang Y, Chen Q, Zanzonico PB, Ling CC, Li GC. Noninvasive molecular imaging of hypoxia in human xenografts: comparing hypoxia-induced gene expression with endogenous and exogenous hypoxia markers. Cancer Res. 2008 Oct 15; 68(20):8597-606.