Because the histological differential diagnosis between type B3 thymoma and thymic carcinoma can be challenging, Khoury et al. [S19] proposed that AR might be useful for pinpointing the diagnosis, particularly because cytoplasmic AR was found in 58.8% (10/17) of type B3 thymomas versus 0% (0/12) of thymic carcinomas [S19]. The gene discussed is AR; the disease is thymic carcinoma.