Within the PPTP/C in vivo models, rhabdomyosarcoma and Wilms tumor models consistently show very high levels of IGF2 expression and low levels of IGF1 expression, while IGF2 expression is lower and more variable for neuroblastoma and osteosarcoma models and is lower still for Ewing sarcoma. The gene discussed is IGF1; the disease is Ewing sarcoma.