ERBB2 and neoplasm: The incidence and the clinical relevance of the presence of overexpression of p53, b-cell lymphoma 2 (bcl-2), avian myelocytomatosis virus oncogene cellular homolog (c-myc), rat sarcoma viral oncogene homolog (ras), and human epidermal growth factor receptor 2 (HER-2) in neoplasms of an occult primitive site have not been assessed and the data reported in the literature are not complete [28,29,30,31,32].