Given that BHB may mediate the resolution of inflammation by inhibiting NLRP3 inflammasome activity,29 and that inflammasome activity contributes to the molecular pathophysiology of many autoimmune diseases including IgG4‐RD,30 it would be interesting to determine whether the low serum BHB observed in patients with IgG4‐RD is a cause or consequence of disease progression in future prospective studies. The gene discussed is NLRP3; the disease is autoimmune disease.