NOS2 and stroke disorder: In stroke mice with MCAO, M1 microglia was found to secrete inflammatory cytokines, comprising tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, IL-12, and IL-23, and enhance the levels of inducible nitric oxide synthase (iNOS) and proteolytic enzymes like MMP9 and MMP3 (Zhao et al., 2020; Zhu et al., 2021).