Valine 777 of HER2 is located in the N-lobe (N-terminal lobe) of the tyrosine kinase domain and results in an elevated kinase activity, an aberrant and enhanced phosphorylation of downstream signaling molecules in cell culture experiments, as well as an increased and more rapid tumor growth compared to wild-type HER2 in xenograft models [18]. Here, ERBB2 is linked to neoplasm.