Introduction You have a breast cancer diagnosis, and the first overwhelming question is often, 'What now?' The search for the right treatment can feel like a maze, especially when you hear that care should be specific to you. A compass that cuts through this confusion is your tumor's biology. Analyzing the specific molecular markers inside your cancer cells, such as HER2, hormone receptors, or BRCA mutations, has changed breast cancer care from a blanket approach into a preci