DRD3 and schizophrenia: This CREB-dependent mechanism may synergize with GSK3β-mediated pathways, as HERV-W env also enhances CREB phosphorylation to upregulate BDNF and dopamine receptor D3 (DRD3), contributing to excitatory-inhibitory imbalances in schizophrenia (Huang et al., 2011).