Similarly to KIT, PDGFRA and their ligands, insulin-like growth factor (IGF)-1 receptor (IGF1R), a type 2 RTK, and its ligands IGF1 and IGF2 play critical roles in normal growth and development, as well as in cellular stress, aging and cancer by stimulating protein synthesis and the cell cycle [14,15]. The gene discussed is IGF1; the disease is cancer.