IL1B and rheumatoid arthritis: In RA joints, macrophages show over-expression of MHC class II and production of proinflammatory cytokines (IL-1β, TNF-α, GM-CSF, and IL-6), chemokines (IL-8, MIP-1α, and MCP-1), metalloproteinases, and neopterin [127], which could drive the disease progression.