LEP and cancer: The IRS2 (Insulin receptor substrate 2) protein plays an important role in the response to stimuli for cytokines and growth factors, like insulin and insulin-like growth factor 1, and promotes proliferation and survival of normal and cancer cells by mediating signaling from INSR, IGF1R, EPOR, MPL, VEGFR, LEP, GH and IFNB1/IFNG proteins.