First, the same cytogenetic and molecular abnormalities suggest that the plasmacytoma in the spleen and myeloma in the bone marrow transformed from the same cell clone, presenting as a classical clonal evolution model from primary Ig rearrangement [t(14;16)] and del(13q) to secondary chromosomal abnormalities (1q21 amplification) and inactivating mutations (a novel CYLD point mutation)[2,23] (Fig. 3). The gene discussed is CYLD; the disease is plasmacytoma.