a, Pearson correlation between the expression of CXCL13 and the 12-chemokine signature of TLS in TCGA SARC cohort (n = 213). Samples are coloured according to SICs. b, Intratumoural location of TLSs in three different examples from the NTUH cohort—DDLPS, UPS and LMS, respectively. TLSs are observed by the presence of CD20+ B cells aggregates (brown, surrounded by blue shapes). The red line delineates the tumoral zone. Similar findings were observed on the 11 tumours with TLS. c, Definition of peripheral, medium and central zones, accounting for 25%, 25% and 50% of the total tumour area, respectively. d, Distribution of TLSs in the various zones. Each bar represents one tumour. The letters above bars indicate the SIC of the tumour when the sample passed quality control of Nanostring nCounter hybridization. Dots indicate tumours in which SIC could not be determined because of RNA quality control. Similar images were observed for 66 E-TLS, 23 PFL-TLS and 20 SFL-TLS. e, Illustration of diverse degrees of TLS maturation in STS tumours. Consistent with maturation events occurring in secondary lymphoid organs, three maturation steps have been described for TLS: E-TLS (bottom), PFL-TLS (middle) and SFL-TLS (top), which differ in the presence of follicular dendritic cells (FDC) and their markers. E-TLS contain aggregates of CD20+ B cells and CD3+ T cells without FDC, PFL-TLS contain CD21+ FDC (red dotted zones) and SFL-TLS contain a germinal centre, notably visible through the presence of CD21+CD23+ follicular dendritic cells (yellow dotted zone). DAPI staining is shown in white. DAPI-negative green dots correspond to fluorescent erythrocytes. f, Distribution of TLS maturation steps in a subset of tumours. Each bar represents one tumour. Differences between the number of TLSs observed here and in other figures can be explained by use of non-consecutive slides or a different tumour block for some samples.