For this, human rhabdomyosarcoma (Rh30) and Ewing sarcoma (Rh1) cells were primarily chosen as models, because these cells, under autocrine conditions, are able to produce large quantity of IGF-II, which has approximately equal affinity to IGF-1 receptor as IGF-1 [34–36]. The gene discussed is IGF2; the disease is Ewing sarcoma.