Although the number of total B cells was lower in ET patients including those with CALR mutations when compared with healthy controls, the number of activated B cells was significantly increased in ET patients across all 3 genotypes that characterized by the expression of CD69 and CD86, increased intracellular IL-6 and IL-1β levels, and higher expression of TLR4. The gene discussed is CD69; the disease is essential thrombocythemia.