The identification of KIT mutations in MC diseases is important because it confers resistance to protein kinase inhibitors such as imatinib [8].The frequency of the D816V KIT mutation in SM is highly variable in the literature, from 29% to virtually all cases [6], [7], [9], [25], [33], and 38% in our SM cohort. Here, WEE1 is linked to systemic mastocytosis.