RCN1 has been demonstrated to be highly expressed in a variety of tumor cells and is correlated with patient prognosis in renal cell carcinoma, prostate cancer, glioblastoma, non‐small cell lung cancer, oral squamous cell carcinoma, nasopharyngeal cancer, colon cancer, laryngeal cancer, highly aggressive breast cancer, sorafenib‐resistant hepatocellular carcinoma cells, and gemcitabine‐insensitive human pancreatic adenocarcinoma cells, among others [20, 21, 22, 24, 25, 27, 55, 56, 57, 58, 59, 60, 61, 62, 63]. This evidence concerns the gene RCN1 and breast cancer.