In addition to promoting M2 phenotype polarization, intranasal delivery of IL-4 nanoparticles poststroke also improves white matter integrity by acting directly on OPCs to enhance oligodendrocyte differentiation mediated by the PPARγ axis, which reduces long-term sensorimotor and cognitive deficits (Zhang Q. et al., 2019). This evidence concerns the gene IL4 and Cognitive impairment.