To assess the prognostic prediction of the interaction between miR-30a and FSCN or between miR-30a and CLDN2 in breast cancer, we defined expression status as “high” (≥ 4.90-fold increase in FSCN mRNA compared with the median) or “low” (< 2.40-fold decrease in CLDN2 mRNA) by comparing expression in cancer cells and adjacent non-cancerous cells. This evidence concerns the gene CLDN2 and breast cancer.