Going beyond cell-based assays, we wanted to determine if the EphA2-binding Abdurins could localize specifically into implanted PC-3 tumors using PET imaging and demonstrate that the localization and accumulation was specific and comparable to a full-length IgG, potentially demonstrating an advantage of greater tumor penetration due to the smaller size of the Abdurins. Here, EPHA2 is linked to neoplasm.