IL1B and Arthritis: CRP can induce the expression of pro‐IL‐1β and NLRP3 and activate the NLRP3 inflammasome in endothelial cells via the FcγR/NF‐kB pathway.[27] Our previous work showed that mast cells are not involved in the pain induced by IgG‐IC.[6] Previous studies on the chronic pain of arthritis have reported that immune cells are not necessary for IgG‐IC‐mediated joint pain.