IL1B and rheumatoid arthritis: In RA, secretion of IL‐1β activates IL‐1 receptor subtype 2 (RII) on neutrophils, monocytes, B cells, and bone marrow cells, triggering the NF‐B signaling cascade to promote leukocyte infiltration, synovial hyperplasia, and joint destruction via the NF‐κB signaling cascade [9, 41, 43, 44].