YAP1 and thymoma: Furthermore, this study highlighted that types A, AB, B, and TC are not a continuum of diseases, but are instead distinct biological entities (5, 19), Recently, metaplastic thymomas were reported to harbor the YAP1-MAML2 translocation, whereas 6% of pretreated types B2 and B3 and a combined TC and B3 thymoma (but not in thymoma and “pure” TCs) may be associated with KMT2A-MAML2 translocation (7).