Maturana MA, et al. - Researchers describe a case of triple-negative myasthenia gravis Lambert-Eaton overlap syndrome with negative Agrin and LRP-4 (low-density lipopro-tein receptor-related protein 4) antibodies. Overall 55 “myasthenia gravis Lambert-Eaton overlap syndrome” (MLOS) cases have been found, of these, 13 were documented prior to the acetylcholine receptor (AChR) antibody (ab) testing era, 14 during the AChR-ab era, 26 during the voltage-gated calcium channel (VGCC)-ab era, and 2 during the muscle-specific kinase (MuSK)-ab era; among these, only 1 patient tested negative for all 3 antibodies. In the study of myasthenia gravis [Agrin and LRP-4], novel immunological markers have been recognized. Here, experts describe a case of MLOS, wherein, the patient tested negative for all 5 (AChR, MuSK, VGCC, Agrin, and LRP-4) serologic markers.