SMAD3 and breast cancer: Based on the results of cluster analysis or potential significance for BC (e.g., [27, 28]), we selected ACVR2A, CCNDs, CCNE1, CDC25A, CDK6, CDKN1B, GHR, CHEK1, IGF1R, IRS1, MAPK1, NCOR, PIK3CA, PIK3CB, RARB, SMAD3, SMAD7, and WEE1 for further determination in tumor samples.