Clinical features of WM include changes of peripheral blood, such as anemia, leukocytosis and increased levels of cytokines and chemokines.11 Peripheral blood samples from BCL2+IL6+AID− mice (n=12) demonstrated similar alterations (Supplementary Table 1), including anemia characterized by a decrease in red blood cells, hemoglobin and hematocrit and a compensatory increase in reticulocytes (Figure 6b, left). The gene discussed is IL6; the disease is anemia (phenotype).