IL1B and Splenomegaly: However, after 24 weeks the platelet count was higher in VF;IL-1β−/− recipients than in VF recipients, and at terminal workup no differences in splenomegaly, grade of reticulin fibrosis or osteosclerosis were detected between the two genotypes (Fig. 4e, f and Supplementary Figs. 6d–f and 8).