AHR and rheumatoid arthritis: In addition, Boule et al. (105) found that developmental exposure to TCDD and subsequent activation of AHR via lactation accelerated disease in Gnaq+/− mice, which are mice that are heterozygous for the Gαq protein and have a genetic predisposition to develop an autoimmune disease with symptoms similar to SLE and RA, but are not guaranteed to develop disease.