CCL19 and neoplasm: Many components secreted by cells in TLS, such as CXCL13, CCL19 [87], and other chemokines, may have their expression or signaling pathways affected by ICB, thereby altering the distribution of immune cells in TLS.It has been discovered that ICB can reverse the suppression of T cells by immune checkpoints and enhance T cell activity, allowing T cells to interact with other immune cells in the TLS and enhance the immune response, thereby recognizing and destroying tumor cells more effectively.