TTN and myasthenia gravis: Anti-titin antibodies are the most thoroughly studied among the intracellular MG autoantigens and, even though they are not expected to contribute to MG pathology, together with the antibodies to ryanodine receptors, they are valuable biomarkers for MG subgroup classification (mostly for the differentiation between MG with or without thymoma) and treatment optimization [11,12,15].