IGHE and allergic disease: In mast cells pre-treated with anti-DNP IgE (IgE), β-hexosaminidase secretion was significantly (P = < 0.05) reduced in BMMCs derived from Rab46−/− mice (blue versus blue stripe columns) compared to BMMCs extracted from Rab46+/+ after DNP (“allergy”) challenge (IgE/DNP: Fig 1h).