CCL2 and glioblastoma: Simultaneously, IL-6, IFN-g, and CCL2 were not transported by exosomes (Figure 2H), suggesting that LRRC4 was not transferred into TILs from GBM cells through exosomes but mainly exerted its inhibitory function on Ti-Treg cell expansion by directly promoting cytokine secretion into the conditioned medium of GBM cells.