FGF4 and gastrointestinal stromal tumor: This result was preceded by a very first identification of a specific gene expression profile shared by qWT GIST samples, with enrichment of Polycomb target genes (in particular of the classes of PRC2 targets and H3K27-bound genes) and of cell cycle progression and MAPK signaling, as exemplified by increased expression of SKP2, CDK6, NTRK2, and FGF4 [18].