SPN and Splenomegaly: Staining for precursor B cell markers [29] revealed that the majority of B cell populations circulating in peripheral blood as well in bone marrow and spleen during the last stages of splenomegaly consisted of B220+CD19+CD43+CD93+CD127+ precursor B cells (Figure 4G, Additional file 1: Figure S1 and Additional file 1: Table S1).