In particular, SM occurred in 5% of patients in the “no therapy” group, in 7% of patients in the “HU” group, in 8% of patients in the “ALK” group, in 8% of patients in the “ALK + HU,” and in 4% of patients in the “ANA/IFN” group (Table 3). Here, IFNA1 is linked to systemic mastocytosis.