RANBP2 and plasmacytoma: The ALK fusion partners identified in this cohort (RANBP2, CLTC, and SEC31A) have been identified previously in IMT and other cancers, including acute myeloid leukemia,48,49 juvenile myelomonocytic leukemia,50 ALCL,51 congenital blastic plasmacytoid dendritic cell neoplasm,52 plasmacytoma,53 B-cell lymphoma,54-60 and lung adenocarcinoma.61 Recurrences occurred in two of three of the patients with RANBP2-ALK translocations, which suggests that this subgroup may be at higher risk of treatment failure despite initial CRs.