Li et al. demonstrated the noninvasive imaging of uPAR expression in a living subject for the first time by using a small linear peptide (D-Cha-F-s-r-Y-L-W-S) (AE105) with high affinity for human uPAR in uPAR xenotransplanted mouse tumor models after labeling with the positron emitter 64Cu [140]. The gene discussed is PLAUR; the disease is neoplasm.