Gene expression profile (GEP) was assessed by performing microarray analysis experiments in a series of 10 PDGFRA mutant GIST patients either carrying a genomic alteration on exon 18 D842V (5 out of 10 samples) or non-D842V mutations, including 2 patients harboring point variants (exon 12 V561D, exon 14 K646E) and three patients showing insertions/deletions (indel) either in exon 12 or exon 18. This evidence concerns the gene PDGFRA and gastrointestinal stromal tumor.