PDGFRA and gastrointestinal stromal tumor: For gene expression analyses, five genes were selected based on their relevance on GIST pathology (i.e. KIT, PDGFRA and DOG1) or due to their importance in angiogenesis and the reasonable efficiency of anti-angiogenic therapy, such as pazopanib and sunitinib, in GIST (i.e. IGF1R and KDR) [28].