In addition to confirming a diagnosis, the presence of such autoantibody can guide the paraneoplastic workup (e.g., the screening for thymoma in anti-AChR+ MG) and treatment (e.g., anti-C5 therapy in anti-AChR+ MG, anti-CD20 therapy in anti-MuSK+ MG and autoimmune nodopathy or IVIg therapy in anti-FGFR3+ sensory neuronopathy). The gene discussed is MUSK; the disease is myasthenia gravis.