 They also participate in transplant rejection, Graft-versus-host disease, and the killing of tumor cells.In conducting these functions, eosinophils produce and release on demand a range of toxic reactive oxygen species (e.g.hypobromite, hypobromous acid, superoxide, and peroxide) and they also release on demand a preformed armamentarium of cytokines, chemokines, growth factors, lipid mediators (e.g.