GABRA5 and thymoma: To quantify the amount of nmTECs, we performed immunostaining for GABRA5 (Fig. 6f) and found that the number of GABRA5-positive cells was higher in MG (P = 0.050) and more significantly in anti-AChR antibody-positive thymoma patients (P = 4.2 × 10−4, Fig. 6g–i).