Schizophrenia is a highly disabling mental disorder, and numerous studies have shown that the hypofunction of the N-methyl-d-aspartate (NMDA) receptor is one of its pathogenic mechanisms. Glycine transporter 1 (GlyT1), a glycine transporter protein, is highly co-localized with the NMDA receptor. Inhibition of GlyT1 can increase the concentration of glycine in the synaptic cleft, thereby indirectly promoting NMDA receptor activation. Therefore, GlyT1 is considered a key target for the treatment of schizophrenia.