IGF2 and cancer: As shown by the quantitative real-time PCR and western blot analysis, IGF-1, IGF-1R and IR expression were not increased in the cixutumumab-treated cancer and stromal cells (Fig. 5a and Supplementary Fig. 11), but cixutumumab treatment induced a significant transcription-dependent IGF-2 production in cancer cells, as shown by quantitative real-time PCR (Fig. 5a) and western blot (Fig. 5b) analyses.