In this study, we identified a novel FN1-FGFR1 fusion gene in three out of four PMTs by next-generation RNA sequencing.     ///    "Interestingly, unlike the prototypical leukaemia-inducing FGFR1 fusion genes, which are ligand-independent, the FN1-FGFR1 chimeric protein was predicted to preserve its ligand-binding domains, suggesting an advantage of the presence of its ligands (such as FGF23 secreted at high levels by the tumour) in the activation of the chimeric receptor tyrosine kinase, thus effecting an autocrine or a paracrine mechanism of tumourigenesis.. "    ///    Identification of a novel FN1-FGFR1 genetic fusion as a frequent event in phosphaturic mesenchymal tumour..     ///    Fluorescence in situ hybridization analysis showed six cases with FN1-FGFR1 fusion out of an additional 11 PMTs. 