PFS of ISM patients classified according to the presence (dotted line) vs absence (full line) of the D816V KIT mutation in BM MSCs. (A) PFS from disease onset for all (n = 83) patients analyzed. (B) Analysis of PFS is restricted to patients (n = 40) with multilineage involvement of hematopoiesis by the KIT D816V mutation with (n = 22) or without (n = 18) D816V KIT-mutated MSCs.