Overall, iron deficiency (ID) decreases T-lymphocyte proliferation, the number of T helper cells (Th) and cytotoxic T cells (CTL) in blood, bactericidal activities of neutrophils and macrophages, reduces TNF and IL-2 production, decreases IFN-γ, IL-12, IL-2, IL-6, and IL-10 levels in human serum, and decreases humoral, cell-mediated and non-specific immunity responsiveness to functional tests of immune function [2]. This evidence concerns the gene IL2 and Iron deficiency anemia.