To further investigate the in vivo effect of GPNMB-directed GSC-TAM bidirectional communication using GBM mouse models, we utilized shRNA knockdown system to deplete GPNMB in macrophages and microglia (Supplemental Figure 2, B–E) and then implanted them together with human and mouse GSC/GBM cells into nude and C57BL/6 mice, respectively. The gene discussed is GPNMB; the disease is glioblastoma.