AHR and rheumatoid arthritis: Some molecules, including extracellular signal-regulated kinase 1/2, arylhydrocarbon receptor, Histone h3, prostaglandin E receptor 2, nuclear factor κappa β (NF-κβ), programmed cell death 5, interleukin (IL)-36, IL-10, IL-4, Hypoxia Inducible Factor 1A, and arachidonate 15-lipoxygenase, are common molecular targets related to APR and RA, with the Eicosanoid signaling pathway the common pathway of APR and RA (Jia et al., 2015).