Eosinophils that infiltrate into tumor environment play both antitumorigenic roles and pro-tumorigenic roles, as they can release interleukins (like IL-10, IL-12 and IFN-γ) or chemokines and growth factors (like EGF, FGF and TGF-β) (Rothenberg and Hogan, 2006; Spencer et al., 2009). The gene discussed is TGFB1; the disease is neoplasm.