Myasthenia gravis (MG) is an autoimmune disease caused by pathogenic autoantibodies targeting the neuromuscular junction (NMJ); these include anti-acetylcholinereceptor (AchR), anti–muscle-specific tyrosine kinase (MuSK), and anti–low-density lipoprotein receptorrelated protein 4 (LRP4) antibodies. The gene discussed is LRP4; the disease is myasthenia gravis.