Consistently, we observed more CD31+ naïve CD4+ T cells in thymoma patients compared to patients with other thymic tumors including thymic cysts, thymic carcinomas, teratomas, and lymphomas (Supplementary Fig. 2a, b), and elevated sjTRECs levels in naïve T cells in thymoma patients compared to age-matched healthy controls or patients with patients with other thymic tumors (Supplementary Fig. 2c), indicating more RTE cells in thymoma patients. Here, PECAM1 is linked to thymus neoplasm.