Full-length monoclonal antibodies are usually labeled with long-half-life radionuclides, such as 64Cu,227–23189Zr,232–234111In,235,236 and 124I.237 Besides, imaging tracers targeting HER2 by shorter fragments (antibody fragments [Fab or F(ab)2], nanobodies, or affibodies) have been introduced into clinical trials, such as 68Ga-DOTA-F(ab0)2-trastuzumab,23868Ga-NOTA-2Rs15d,171 ABY-002 labeled with 111In and 68Ga,239111In-ABY-025,17468Ga-ABY-025,17599mTc-ADAPT6,240 and 99mTc-(HE)3-G3,241 to assess HER2 expression in breast carcinoma. This evidence concerns the gene ERBB2 and breast carcinoma.