IGF2 and breast cancer: Previously, in the clinical trials, various strategies (monoclonal antibodies against IGF-1R, monoclonal antibodies against IGF-1R ligands (IGF-1 and IGF-2), and IGF-1R tyrosine kinase inhibitors) have been used to control the expression levels of IGF-1R which gets over expressed in about 50% of the cases of breast cancer [15].