Regarding the evaluation of TLSs, we simply explored the CD20-positive cells, although there are several methods to evaluate the details of TLSs, such as CD21-positive cells and CD23-positive cells that classify the phenotype of TLSs, several T-cell markers contained in TLSs, and the chemokines associated with TLSs.13,19,20 If we evaluate TLSs in detail as mentioned above, we may elucidate the function of TLSs on pulmonary metastases from uterine leiomyosarcoma. This evidence concerns the gene CR2 and leiomyosarcoma.