P021, a tetra-peptide derived from the biologically active region of the human ciliary neurotrophic factor (CNTF), was found to enhance neurogenesis and synaptic plasticity by promoting an increase in BDNF expression in preclinical models of brain disorders, such as Alzheimer’s disease and Down syndrome, resulting in a beneficial therapeutic effect. The gene discussed is CNTF; the disease is early-onset autosomal dominant Alzheimer disease.