Taken together, we suggest that the Trx1 blood test itself is reliable for diagnosing breast cancer or as a screening test for early detection of breast cancer, and moreover that the combinational use of Trx1 with either CEA or CA15-3 overcomes their problems (poor sensitivity) encountered in diagnosis by the CEA or CA15-3 test alone. This evidence concerns the gene CEACAM5 and breast carcinoma.