Although human clinical studies have not investigated levels of the IR in breast tumors from hyperinsulinemic patients, specifically, it has been reported that IR expression, as well as being a strong predictor of poor survival rate, spans all three subsets of clinical breast cancer (luminal, Her2 positive and triple negative) [9,10], and mammary tumorigenesis in mice resulting from transgenic expression of Neu, Wnt1, or Ret oncogenes is accompanied by significant elevations of IR levels in all three tumor types [51]. This evidence concerns the gene RET and breast cancer.