Activating mutations of KIT were found in 88,2% (n = 127) of gastrointestinal stromal tumors (GISTs) and showed a significantly higher partial response rate to imatinib for exon 11 KIT mutation (83.5%) compared to exon 9 KIT mutation (47.8%) or no found mutation (0.0%) [53]. This evidence concerns the gene KIT and gastrointestinal stromal tumor.