A subset of GIST lack specific KIT or PDGFRA mutations and form a heterogeneous group, including NF1, Carney Triad (CT), Carney-Stratakis Syndrome (CSS), pediatric and young adult GIST, and a small proportion (<10%) of sporadic adult GIST [3-8]. Here, PDGFRA is linked to gastrointestinal stromal tumor.