Triple-negative breast cancer is a type of breast cancer that lacks estrogen receptors, progesterone receptors, and HER2 proteins. Synonyms for this type of breast cancer include basal-like breast cancer and receptor-negative breast cancer. Basal-like breast cancer is named after the specific group of cells where the cancer originates, and it is also known as triple negative because the cells lack the three receptors mentioned above. Receptor-negative breast cancer is a broader term that encompasses not only triple-negative breast cancer but also other types of breast cancer that do not respond to hormone treatments. These synonyms help medical professionals better understand the type of breast cancer a patient may have and develop an appropriate treatment plan.