Additionally, in another series of quadruple wild-type GIST, focal duplication of band 11q13.3 (involving FGF3/FGF4) was identified in 6/8 patients and this event was associated with the overexpression of FGF4, one of the most important ligands of FGFR1 [11] (Figure 1B). The gene discussed is FGF4; the disease is gastrointestinal stromal tumor.