Abstract Cancer-associated fibroblasts (CAFs) shape how immune cells are organized within tumors and either support or hinder the formation of immune niches associated with clinical outcomes and treatment response known as tertiary lymphoid structures (TLSs). Some CAF states support immune-cell recruitment and TLS establishment, whereas others create dense, fibrotic environments that restrict immune organization. Importantly, the presence of TLSs does not by itself indicate antitumor immunity.
