Immunohistochemistry was performed to study the expression of ALK, HER2, HER3, MET, phospho-mTOR, p16INK4A, PDGFRA, PDGFRB, PD-L1, PTEN and ROS1 in type A and B3 thymomas and thymic carcinomas. The gene discussed is PDGFRB; the disease is thymic carcinoma.