Mast cells and basophils are known to express FcεRI and to participate in parasite clearance through IgE.19 The rat basophilic leukemia RBL SX-38 in vitro mast cell model expressing human FcεRI, was used to examine the Fc-mediated biological activities of SF-25 IgE.20 We investigated the Fc-mediated functions of SF-25 IgE to trigger mast cell degranulation when cross-linked by multiple copies of its target antigen expressed on the surface of cancer cell lines A2058, IGROV1, SKBR-3 and LS-180. Here, IGHE is linked to acute basophilic leukemia.