Comprehensive characterization of these structural variants established that GFI1/GFI1B expression becomes activated through relocation of their coding sequences to genomic regions of transcriptionally active chromatin.     ///    Functional analyses performed in mice confirmed the oncogenicity of Gfi1/Gfi1b in the context of medulloblastoma and demonstrated apparent synergy between both of these candidates and the c-Myc oncogene. 