Incubation with figitumumab reduced the amount of the type I IGF receptor and the activation of Akt by phosphorylation of Ser473, which indicates that the type I IGF receptor and the IGF signal transduction pathway are major activators of the PI3-kinase/Akt pathway in oestrogen-responsive breast cancer cells (Fig. 8D). This evidence concerns the gene AKT1 and breast carcinoma.