CXCL13 and neoplasm: Tertiary lymphoid structures (TLS) are B‐cell follicle‐like immune cell aggregates found in tumors.[116] Intra‐tumoral CD8+ T cells are frequently located inside or surrounding TLS,[59, 117, 118] especially the stem‐like TCF1+ CD8+ T cells.[81] Mechanistically, tumor‐reactive CD8+ T cells express TLS‐forming CXCL13,[87] and TEXprog cells are characterized by the expression of the CXCL13 receptor, CXCR5.[116] As tumor‐reactive CD8+ T cells become exhausted, they upregulate CXCL13 expression and initiate TLS formation.