Moynihan, M.D. HER2-positive breast cancer is a breast cancer that tests positive for a protein called human epidermal growth factor receptor 2 (HER2), which promotes the growth of cancer cells. In about 1 of every 5 breast cancers, the cancer cells have a gene mutation that makes an excess of the HER2 protein.
HER2 (human epidermal growth factor receptor 2) is a gene that can play a role in the development of breast cancer.. The HER2 gene makes HER2 proteins (also sometimes referred to as HER2/neu proteins). HER2 proteins are receptors on breast cells.
HER2 (human epidermal growth factor receptor 2) is a protein that appears on the surface of some breast cancer cells. It may also be called HER2/neu or ErbB2