In a therapeutic in vivo model, increased Bet v 1-specific IgG1 levels induced by intraperitoneal injections of BM4 were associated with a downregulation in Bet v 1-triggered mediator release using rat basophilic leukemia cells, as well as a general decrease of Th2-mediated inflammation as judged by BALF IL5 cytokine secretion and lung infiltrating cells (20). This evidence concerns the gene IL5 and acute basophilic leukemia.