IL1B and Stroke: In animal experiments, overexpression of interleukin (IL)‐1a, IL‐1b, IL‐1 receptor antagonist (IL‐1ra), IL‐6, and TNF‐α has been found in the brain after stroke (Hill et al., 1999; Legos et al., 2000; Zhai, Futrell, & Chen, 1997).