CXCL13 and neoplasm: The initial stage of TLS formation partially depends on the secretion of IL-7 and CXCL13 by stromal cells and lymphocytes at the site of inflammation or high tumor mutation burden (TMB) 7, supporting the recruitment of lymphoid tissue inducing cells (LTi cells) such as Th17 cells, B cells, macrophages and innate lymphoid cell-3 (ILC3s) 8.