ERBB2 and breast cancer: Therefore, our results reiterate that the allelic heterogeneity is found in early human breast lesions and are in agreement with those of various authors who consider the human ERBB2 proto-oncogene to be a natural target for sequence variant analysis [49], as the encoded transmembrane tyrosine kinase receptor protein is highly recognised to have an important role in human breast cancer prognosis [49]–[51].