To validate gene expression results, we first examined the levels of LINC00174 and LINC00174-related 5-genes signature (UBAC1, FEM1B, CCDC30, SYBU, and SCD5) in the fresh frozen thymoma and normal tissue samples used for microarrays, and in primary cell culture from normal (peritumoral thymic tissue) and neoplastic thymic tissues (Supplementary Fig. 2A, B). Here, FEM1B is linked to thymoma.