PTGS2 and arthritic joint disease: SGR active compounds such as quercetin, naringenin, beta-sitosterol, and epicatechin interact with a group of proteins, such as TNF, AKT1, IL6, IL-1β, VEGFA, TP53, CASP3, PTGS2, JUN, and EGF, to regulate/modulate abnormal immune responses observed in arthritis.