GL261-GSCs-derived exosomes induce macrophage M2 polarization: (a) representative image from an electron microscope of exosomes collected from the culture medium of GL261 and GL261-GSC cells; (b) proteins are extracted from the exosomes of GL261 cells and the expression of CD9, CD81, TSG101, calnexin, and albumin is determined by Western blot analysis; (c) particle size map of exosomes from GL261 and GL261-GSC cells, and standard substance is used as a comparison; (d) relative quantitative results of the Griess experiment in the culture medium of BMDMs cultured with the exosomes from GL261 or GL261-GSC cells (n = 3); (e) relative quantitative results of ELISA experiment of TGF-β and IL10 protein levels in the culture medium of BMDMs cultured with the exosomes from GL261 or GL261-GSC cells; (f) relative quantitative results of qRT-PCR analysis of the expression TGF-β, CD206, Arg-1, and IL-10 in BMDMs cultured with the exosomes from GL261 or GL261-GSC cells. GAPDH is used as a reference gene (n = 3). Data are presented as the mean ± S.D. p-value is determined by ordinary one-way ANOVA (* p < 0.05, ** p < 0.01, *** p < 0.001, **** p < 0.0001).