NASHVILLE — Scientists at Vanderbilt University Medical Center have drawn one of the most detailed molecular maps of breast cancer ever assembled, charting more than 7,600 tumors into a single atlas that reveals hidden subtypes of the disease, including an aggressive form of triple-negative breast cancer that had previously gone unrecognized. The work, published online Tuesday, Nov. 3, 2026, in Cell Reports Medicine , offers a new foundation for matching patients with treatments based on the molecular fingerprint of their tumor rather than on standard pathology alone. Illustration: A stylized molecular map of breast cancer tumor diversity, with glowing cell clusters connected in a data-visualization network. What Happened Researchers at Vanderbilt-Ingram Cancer Center harmonized 7,612 bulk breast-cancer transcriptomes drawn from 22 independent datasets, creating one of the largest transcriptomic maps of breast cancer ever assembled. The transcriptome is the complete set of RNA ...