The hypofunctional 677T variant in the methylenetetrahydrofolate reductase gene (MTHFR 677C>T, rs1801133) has been associated with increased risk for schizophrenia (Gilbody et al., 2007; Allen et al., 2008), executive dysfunction in schizophrenia (Roffman et al., 2008b), and negative symptoms (Roffman et al., 2008c). The gene discussed is MTHFR; the disease is schizophrenia.