CXCL13 and neoplasm: At the onset of the TLS formation, stromal cells or lymphocytes present at sites of chronic inflammation or tumor secrete chemokines such as CXCL13 and IL-7, thereby attracting lymphoid tissue-inducing (LTi) cells to the tumor site; B cells, Th17 cells, and M1 macrophages act as potential LTi cell candidates.