For example, transcripts encoding the cadherin Fat2, which plays an important role in cerebellum development, the amino acid oxidase Dao, which may be involved in schizophrenia, the tryptophan hydroxylase 2 (Tph2), which is responsible for the biosynthesis of serotonin, the dopamine β-hydroxylase (Dbh), which converts dopamine to norepinephrine, the inhibitory neurotransmitter Gabra6 and the neurotransmitter transporters Slc6a2, Slc6a4 and Slc6a5 were expressed predominantly in the brainstem. Here, TPH2 is linked to schizophrenia.