KIT and gastrointestinal stromal tumor: KIT mutations, usually occur at the intracellular juxtamembrane (JM) WW domain (encoded by exon 11), or in the membrane-proximal extracellular domain (encoded by exons 8 or 9), accounting for approximately 85–90% of KIT-mutant GIST, they endows KIT gene an oncogenic capacity to proliferate and form tumors via the intermediates of PI3K-AKT, JAK-STAT and RAS-RAF-MEK-ERK (MAPK) cascades [9, 12, 17–19].