Studies have also shown a link between schizophrenia and polymorphisms of manganese superoxide dismutase (Mn-SOD) synthesis genes: a comparative proteomic analysis of postmortem human hippocampal tissue samples revealed that the concentration of Mn-SOD is significantly diminished in the hippocampus of a schizophrenia patient [16]. The gene discussed is SOD2; the disease is schizophrenia.