Expression of the SS18-SSX2 fusion, which molecularly characterises SS, results in transcriptional upregulation of FGFR2 and increased expression of FGF ligands, FGF3, FGF7, FGF9 and FGF18, suggesting possible autocrine feedback loops function to upregulate FGFR signalling [91]. This evidence concerns the gene SS18 and synovial sarcoma.