ERBB2 becomes significant in the context of cancer when it is overexpressed or amplified. Overexpression of the ERBB2 gene leads to an increased amount of the HER2 protein on the cell surface. This overabundance can cause cells to grow and divide uncontrollably, contributing to the formation and progression of malignant tumors. HER2-positive cancers are particularly aggressive and are associated with a poor prognosis.
