CEBPZ and gastrointestinal stromal tumor: KIT mutations have been reported in more than 90% of cases of mast cytosis [44], 80–85% of cases of gastrointestinal stromal tumor (GIST) [45], 10–20% of cases of melanoma [46] and 4–17% of cases of AML [47], primarily core-binding factor AML (CBF-AML; ~30%) [48].