CXCL13 and breast cancer: Importantly, as reported previously, TILs in breast cancer can form organized tertiary lymphoid structures (TLSs) characterized by CXCL13+ T follicular helper (Tfh) cells (30), and high levels of CXCL13+ T cells are associated with the response to PD-L1 blockade in TNBC according to a single-cell RNA- and ATAC-sequencing analysis in 22 patients with advanced TNBC treated with paclitaxel alone or in combination with the anti-PD-L1 atezolizumab (31).