A clinical study has also indicated that CDCP1 may enhance the activity of TGF-β1 signal transducers,[27] and another study has shown a positive correlation between TGF-β levels in normal epithelial breast tissue and SD.[28] These studies highlighted the likeliness that CDCP1 may cause SD via increasing TGF-β activity, providing possible explanations and theoretical support for our results. This evidence concerns the gene CDCP1 and Salla disease.