Previously, there were some reports about nanobodies targeting HER2: combining nanobodies targeting HER2 with photochemical internalization (PCI) on polymerized nanoparticles (NPs) that carry saponin achieved the selectivity of NPs (25); a combination of liposome and HER2-nanobody facilitated the localization of breast cancer cells by magnetic resonance imaging (MRI) (26); HER2-nanobody radiolabeled with 131I, 18F, or 117Lu pinpointed and evaluated HER2 protein expression and localization (27–29). Here, ERBB2 is linked to breast cancer.