BDNF and schizophrenia: Moreover, transcriptional activation of HERVs is associated with the development of SCZ; specifically, HERV-W env gene regulates the expression of schizophrenia-associated genes, such as the brain-derived neurotrophic factor (BDNF), neurotrophic tyrosine kinase receptor type 2 (NTRK2), and dopamine receptor D3 (DRD3) [175].