In several diseases, due to iron overload, such as hereditary hemochromatosis, an impairment of the main functions of macrophages has been observed, especially in the phagocytic activity (a decrease of 62.5% compared with healthy donors) [58] and in the bactericidal activity via, for example, a deficiency of the secretion of TNF (it is in between 1.9 and 7.0 times lower than the healthy control depending on the period of incubation with LPS) [59]. This evidence concerns the gene TNF and Tangier disease.