Although further research is needed in order to elucidate the expression regulation and biological functions of, for example, CD300f in basophils, as well as the implication of CD300c in mast cell-dependent reactions, there is accumulating evidence that CD300-mediated signals are able to modulate the activation of basophils, eosinophils and mast cells in allergic responses promoting or suppressing the pathogenesis of certain allergic diseases. The gene discussed is CD300C; the disease is allergic disease.