Immunohistochemistry—10 single patient TMA with normal breast epithelium, invasive cancer or lymph node metastasis.Transfection of MCF-7 cells with CMV-CART construct—Western blot.Treatment of MCF-7 cells with recombinant human CART42–89 peptide—Western blot, Luciferase reporter assay.Manual cytoplasmic intensity score and automated image analysis—CART protein expression in two independent breast cancer cohorts.MCF-7 and T47D cells (response to tamoxifen measurement)—fluorescence-activated cell sorting analysis.3rd cohort—patients under tamoxifen treatment. This evidence concerns the gene CARTPT and breast cancer.