Pursuing the idea of an AAVMUSE-based gene therapy to treat NAFLD, we chose a synthetic recombinant Fc-FGF21 variant (ΔhFGF21) as the intervention36,37; this protein has been examined in a clinical Phase II trial designed to reduce hepatic fat in subjects with NAFLD38. The gene discussed is FGF21; the disease is metabolic dysfunction-associated steatotic liver disease.