With the aim to better characterize this KNGL patient, an expression analysis of genes involved in both regulation of KIT expression: MIR221 and MIR222 [21]; as well as in the pathogenesis of GIST: KIT, PDGFRA, DOG1 [22, 23] and IGF1R and KDR [24, 25], along with a KIT and PDGFRA mutational screening and pathologic review was performed. The gene discussed is PDGFRA; the disease is gastrointestinal stromal tumor.