RYR2 and thymoma: However, by comparing anti-RYR and anti-TTN antibody-positive MG patientswith seronegative non-MG thymoma patients, we observed that MG patients with type A/AB thymoma, who were all positive for anti-RYR1 antibodies, had a lower intra-thymoma RYR1 expression, associated with AIRE down-regulation, compared to seronegative non-MG patients with thymoma of the same WHO type (Figure 7a).