Describes cancer cells that do not have a large amount of a protein called HER2 on their surface. In normal cells, HER2 helps to control cell growth. Cancer cells that are HER2 negative may grow more slowly and are less likely to recur (come back) or spread to other parts of the body than cancer cells that have a large amount of HER2 on their surface. Checking for the amount of HER2 on some types of cancer cells may help plan treatment. These cancers include breast, bladder, ovarian, pancreatic, and stomach cancers. Also called human epidermal growth factor receptor 2 negative.