Pharmacological concentrations of tamoxifen induce proapoptotic effects in ER-ve breast cancer cells, via the activation/inactivation of signaling pathways that involve phosphatidylinositol 3-kinase (PI3K)/Akt, extracellular-signal-regulated kinase (ERK), and insulin-like growth factor 1 receptor (IGF-1R) [20]. This evidence concerns the gene IGF1R and breast carcinoma.