To validate data derived from the DNA methylation array, we focused on the only three genes carrying specific aberrant methylation in TNBC but not in other BC subtypes: VWCE, TSPAN9 and ADAM12. For each gene, the methylation status of a region covering the DMP in the array and some contiguous CpG sites was analysed by pyrosequencing in a larger series of 50 TNBCs and 24 non-neoplastic breast tissues. Here, TSPAN9 is linked to breast cancer.