This approach increased the tumor-to-liver ratio by ca. 7-fold for EGFR-targeting affibody molecules from 0.46 for [111In]In-DOTA-Z2377 (4 h pi) [53] to 3.1 for [57Co]Co-DOTA-Z2377 (3 h pi) [54] in an A431 xenograft model. Here, EGFR is linked to neoplasm.