For example, significant DNA hypermethylation of APC and RARβ2 were detected in the serum of patients with malignant BC as compared to serum from subjects with benign lesions and healthy controls, with both sensitivities and specificities of these two methylated genes being superior to traditional tumor markers (CEA and CA 15-3) for BC detection (58). This evidence concerns the gene CEACAM5 and breast cancer.