Mn exclusion from the rat diet led to anemia, worsened the body’s immune response, and caused systemic and local inflammation as indicated e.g. by decreased RBC, HCT, and the level of HGB, and CRP in blood, CRP and IgA in the jejunum, and IgG in the brain as well as an increased level of IL-2, IgG and TNF-α in blood, and IL-6 in jejunum. The gene discussed is TNF; the disease is anemia (phenotype).