Guo et al. explored the anti-infarct effect of paeoniflorin (PF), the principle component of P. radix (Shao Yao), in the subacute phase of cerebral I/R injury and reported that PF protects against cerebral infarction mainly through TNF-α, IL-1β, iNOS, COX-2, and 5-LO downregulation in the ischemic area 14 d after reperfusion [56]. The gene discussed is PTGS2; the disease is brain infarction.