A cofactor for factor XI activation.

mice carry mutations of the c-Kit gene, which obviously do not affect basophil biology. On the other hand, basophil-deficient Mcpt8DTR or basoph8 mice carry a transgenic receptor that mediates toxin-mediated cell death and mast cells in these mice remain intact. In mice deficient in IL-3, both mast cell and basophil generation are severely impaired only after parasite infection.6 Therefore, Cpa3-Cre; Mcl-1fl/fl mice will prove a useful animal model from which both redundant and nonredundant functions of mast cells and basophils in vivo can be unveiled. Conflict-of-interest disclosure: The author declares no competing financial interests. ■