IGF2 and sarcoma: A preliminary phase I trial report for figitumumab in combination with the mTOR inhibitor everolimus has shown activity in various sarcomas, including solitary fibrous tumors [104], which are characterised by the expression and secretion of high molecular weight proforms of IGF2 (“big”-IGF2) [105, 106] and constitutive activation of IR-A but not IGF1R [64].