One of the most promising of these is the affibody ZEGFR:1907 (Figure 1B), which exhibits a high affinity to the EGFR (Kd of 5.4 nM [12]) and has already been used in 18F- and 64Cu-labeled form for the imaging of EGFR-expressing human tumor cells in xenografted mice [13,14]. Here, EGFR is linked to neoplasm.