Use of antihistamine or anti-allergic agents (e.g., oxatomide, astemizole, olopatadine) in the in vitro models of allergies or basophilic leukemia cells (RBL-2H3) seem to suppress one or a combination of interdependent MCs responses such as inhibition of AA pathways, cytokines (e.g., IL-4) or Ca2+ influx through receptor-operated channels (ROC), phosphorylation of P38 mitogen-activated protein kinase (MAPK) and c-Jun NH2-terminal kinase, pathways that are involved in IL-4 gene expression and tumorigenesis (anabolic pathways)? This evidence concerns the gene IL4 and acute basophilic leukemia.