Myasthenia gravis is an autoimmune disease that is associated with antibodies directed against nicotinic acetylcholine receptors (AChRs) on the postsynaptic membrane at the neuromuscular junction, or against other proteins, such as muscle-specific tyrosine kinase (MuSK), low-density lipoprotein receptor-related protein 4 (LRP4), and agrin, which are involved in AChR clustering on the postsynaptic membrane and in structural maintenance of the neuromuscular synapse [1,2]. The gene discussed is LRP4; the disease is myasthenia gravis.