SOD2 and infection: We then evaluated the effect of Tc infection on the expression levels of the mammalian superoxide dismutases, including copper- and zinc-containing, cytosolic, homodimer enzyme (SOD1 or CuZnSOD), manganese-containing, mitochondrial, tetramer enzyme (SOD2 or MnSOD), and copper- and zinc-containing tetramer enzyme that is secreted to extracellular spaces (SOD3 or ECSOD) in WT and MnSOD+/- mice.