As cixutumumab (an IGF-1R inhibitor) monotherapy demonstrated limited single-agent activity in a phase 2 trial (ClinicalTrials.gov identifier: NCT00831844) in ES patients, a combination of cixutumumab and temsirolimus was used, revealing that 31% of patients achieved stable disease (SD) for more than 5 months and 29% of patients demonstrated more than 20% tumor regression (Naing et al., 2012). Here, IGF1R is linked to Ewing sarcoma.