The mechanisms by which these recurrent structural changes have oncogenic effects have been identified for osteosarcoma (translocations limited to the first intron of TP53) and medulloblastoma (structural variants that juxtapose sequences of GFI1 (Growth Factor Independent 1 Transcriptional Repressor) or GFI1B (Growth Factor) Independent 1 Transcriptional Repressor B) that are proximal to the enhancer elements [58,59]. The gene discussed is GFI1B; the disease is medulloblastoma.