ERBB2 and neoplasm: The main hypothesis of the study was that different macrocyclic chelators have a different influence on the biodistribution of 68Ga-labeled synthetic Affibody molecules, and comparison of labeled synthetic HER2-targeting Affibody molecules using DOTA, NOTA and NODAGA conjugated to the N-terminus of the protein by amide bonds would enable us to select a 68Ga-labeled conjugate with the highest tumor-to-organ ratio (i.e. imaging contrast).