Interestingly, when delivered intranasally and after reaching the TME via nose-to-brain transport, galectin-1 siRNA chitosan NPs silenced galectin-1 in the TME and induced a remarkable switch in the TME composition, including a reduction in macrophage polarization from M1 towards the M2 phenotype during GBM progression [219]. This evidence concerns the gene LGALS1 and glioblastoma.