Furthermore, immunohistochemical analysis showed an aberrant expression of PIT-1 in the neoplastic cortical thymic epithelial cells in patient 1 (Fig. 2c) and 2 (Fig. 2d) in contrast to those cells in thymoma with (Fig. 2e) or without MG (Fig. 2f), or thymus cells (Fig. 2g). Here, POU1F1 is linked to thymoma.