Here, we provide experimental evidence that these general mechanisms also apply to thymic carcinomas: up to 50% of thymic carcinomas showed strong immunohistochemical expression of immunoproteasome subunits: i) epithelial cells of thymomas and thymic carcinomas showed functional activity of the immunoproteasome subunits β1i (PSMB9), β2i (PSMB10), and β5i (PSMB8). Here, PSMB9 is linked to thymic carcinoma.