The insulin-like growth factor-II(IGF-2) is a potent mitogen that plays an essential role not only in normal growth and development, but also in breast cancer susceptibility, growth and progression by signalling the IGF1 and insulin receptors [31]–[35] .The proliferation of breast cancer cells in culture is also responsive to insulin-like growth factors, and components of the IGF-1signal transduction system are expressed by both breast tumors and cultured breast cancer cells. The gene discussed is INSR; the disease is breast cancer.