For example, proinflammatory cytokines, such as interleukin (IL)-1β, IL-2, and IFN-γ, CXC motif chemokine ligand 9 (CXCL9), CXCL10, inducible nitric oxide synthase (iNOS), and cyclooxygenase 2 (COX-2), can aggravate symptoms after stroke. This evidence concerns the gene NOS2 and stroke disorder.