Fig 2: Co-culture experiment of M1 macrophages and U251 cells. a, c. Schematic diagram of a co-culture of M1 macrophages and U251 cells in the empty vector group and FNDC4-overexpression group. b, d. Fluorescent antibodies and flow cytometry were used to detect the surface markers of macrophages. e. Statistical results of the expression of U251 cell-line surface markers. (Data are presented as mean ± SE.)

Fig 3: Effect of exogenous FNDC4 on polarization of M0 macrophages. a. Analysis of FNDC4 promoting polarization of M0 macrophages towards M1 direction: Compared with M0, the CD80/CD206 ratio of M0 + LPS was significantly increased. Compared with M0 + FNDC4, the CD80/CD206 ratio of M0 + LPS + FNDC4 was also significantly increased. However, compared with M0 + LPS, the CD80/CD206 of M0 + LPS + FNDC4 decreased significantly. b. Analysis of FNDC4 promoting polarization of M0 macrophages towards M2 direction: Compared with M0, the CD80/CD206 ratio of M0 + IL-4 was significantly increased. Compared with M0 + FNDC4, the CD80/CD206 ratio of M0 + IL-4 + FNDC4 was also significantly increased. However, compared with M0 + IL-4, the CD80/CD206 of M0 + IL-4 + FNDC4 has barely changed. (Data are presented as mean ± SE; “***” represents p value less than 0.001; “****” represents a p value less than 0.0001)

Fig 4: Verification of FNDC4 overexpression efficiency. a. FNDC4 overexpression verified by western blotting bands. b. Statistical analysis of exocrine FNDC4 overexpression was verified by ELISA. (Data are presented as mean ± SE)

Fig 5: Bioinformatics analysis of FNDC4 in glioblastoma. a. Differential expression analysis of FNDC4 from TCGA database. b. Differential expression analysis of FNDC4 from CGGA database. c. Survival analysis of FNDC4 from TCGA database. d. Survival analysis of FNDC4 expression from CGGA database