Expression of CAIX and Glut-1 in only the invasive lesion of non-BRCA mutation carriers occurred in 8% (4/50) and 10% (5/50) of cases, respectively, whereas these markers were expressed only in DCIS lesions in 4% (2/50) and 44% (22/50) of cases. This evidence concerns the gene SLC2A1 and ductal breast carcinoma in situ.