In order to facilitate translation of transferrin-conjugated probes and therapeutics in breast cancer, we set out to characterize the expression of TfR throughout large datasets and [8, 25, 26] ad-hoc collections of breast cancer histological specimens, with a particular focus on the inclusion of post-chemotherapy and metastatic lesions, which are often underrepresented in discovery studies. The gene discussed is TFRC; the disease is breast carcinoma.