GLI1 and Ewing sarcoma: For instance, the Ewing Sarcoma/Friend Leukemia Integration 1 (EWS/FLI1) fusion oncogene, that characterizes Ewing Sarcoma Family Tumors (ESFT), has been shown to induce GLI1 transcription via direct binding to GLI1 promoter, with a consequent increase in the expression of activated GLI1 protein (Zwerner et al., 2008; Beauchamp et al., 2009).