IL1B and essential thrombocythemia: When compared to healthy adults, patients with ET had statistically significant higher serum BAFF level and higher MFI of mBAFF on both granulocytes and monocytes (Figure 1), and higher fraction of B cells with TLR4 expression and higher fractions of B cells with intracellular IL-1β and IL-6 expression irrespective of their genotypes (Figure 2) (Table 2).