The authors observed both beneficial (dose-dependent increase in T cell proliferation, IL-8, IL-10, and IFN-γ) and detrimental (lower granzyme B content of CD8 cells and suppressed synthesis of tumor necrosis factor-alpha, TNF-α) effects of Se supplementation on cellular immunity to influenza, supporting the hypothesis that concentration of Se has a narrow effective range [142]. This evidence concerns the gene TNF and influenza.