ERBB2 and neoplasm: The affibody molecules, which are only 1/20th the molecular weight of antibodies, enable efficient tumor penetration, resulting in rapid tumor localization, rapid clearance from the bloodstream and other unspecified tissues, and hold great promise in molecular imaging and molecularly targeted therapies for tumours [13]. As of today, there are more than 50 types of affibody molecules in development, such as HER2 [14], epidermal growth factor receptor (EGFR) [15], melanoma antigen A3 (MAGE-A3) [16], and HPV 16/18 E7 [17, 18].