NRAS and systemic mastocytosis: Among AdvSM patients, mutations in most of these genes (e.g., ASXL1, CBL, JAK2, KRAS, NRAS, RUNX1, SRSF2 and TET2) have been reported to be more frequently associated with SM-AHN than ASM, with only a few exceptions that involve genes that show similarly mutated frequencies in both subtypes of SM (i.e., DNMT3A, EZH2 and SF3B1) (Table 4 and Table 5).