IL4 and stroke disorder: M2 phenotype is anti-inflammatory, which secretes anti-inflammatory cytokines such as interleukin-4 (IL-4), interleukin-10 (IL-10), transforming growth factor-β (TGF-β) and some neurotrophic factors, which facilitate brain function recovery and improve the prognosis of stroke (Hu et al., 2012; Liu et al., 2016; Shu et al., 2016).