ERBB2 and breast cancer: The information presented in this reviewallows for a more detailed look at the evolution of the radionuclidediagnostics of HER2- positive BC using various compounds as a targeting module:from full-length antibodies to a new group of small synthetic proteins, namelyalternative scaffold proteins, which are present in various molecular formswith different structures, charges, and lipophilicity of the amino acidresidues exposed to a solvent.