Additionally, bioactive molecules with neurotropic or neuroprotective properties can be delivered to potentially mediate the ND targeting pathways, e.g., neurotrophin deficiency, impaired lipid metabolism, mitochondrial dysfunction, endoplasmic reticulum stress, accumulation of misfolded proteins or peptide fragments, toxic protein aggregates, oxidative stress damage, and neuroinflammation. The gene discussed is BDNF; the disease is hyperinsulinemic hypoglycemia, familial, 4.