It was reported that mutant allele of rs9651118 was associated with reduced lung cancer risk in never smokers, and a nominally significant association with schizophrenia in the form of haplotypes (rs1801133, rs17421511, rs17037396, and rs9651118) in the MTHFR gene in a Japanese population [30,31]. Here, MTHFR is linked to schizophrenia.