This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Chronic Myelogenous Leukemia, Subject name: Pathology
Which of the following gene mutations is most commonly associated with systemic mastocytosis? 
Select and explain. 
A. CALR, B. JAK2, C. KIT, D. MPL
C: KIT
Answer: C: KIT 
Explanation: Myeloproliferative neoplasms Disorder Mutation/Translocation Chronic myeloid leukemia BCR-ABL1 fusion/translocation Polycythemia vera JAK2 mutations Essential thrombocythemia/Primary myelofibrosis JAK2, CALR, MPL mutations Systemic mastocytosis KIT mutations Chronic eosinophilic leukemia FIP1L1-PDGFRA fusion genePDE4DIP-PDGFRB fusion gene Chronic neutrophilic leukemia CSF3R mutations Myeloid neoplasms with eosinophilia Various fusion genes involving FGFR1, PDGFRA, PDGFRB, or JAK2