Immunological parameters such as assays of thymulin activity and lymphocyte ecto-5′-nucleotidase, a marker of lymphocyte maturity, and determination of mRNAs of IL-2 and IFN-γ after PHA and PMA stimulation of mononuclear cells in peripheral blood may be very sensitive and useful biomarkers of human zinc deficiency. This evidence concerns the gene IL2 and Zinc deficiency.