LRP4 and myasthenia gravis: In recent years, new Abs have been discovered in some of the MG patients targeted against lipoprotein-receptor-related protein 4 (LRP4), agrin, acetylcholinesterase (AChE)/collagen Q (ColQ), anti-striational muscle [that is, Kv1.4 potassium channel, titin, and ryanodine receptors (RyR)] and cortactin antigens at NMJ (11, 12).