ERBB2 and cancer: Currently, the two major categories of antigens are considered promising candidates: (1) tumor-associated antigens (TAAs) which are abnormally expressed self-proteins [54] including surface oncogenes (HER2) [55], cell lineage differentiation antigens (PSA) [56], or other mutations (BCR-ABL1) [57]; and (2) oncogenic viral antigens (HBV, HPV etc.), found in virus-driven cancers, which account for approximatively16% of all cancers [58].