In addition, other inflammatory factors such as IL‐12, IL‐15, IL‐18, IL‐32, GM‐CSF, and chemokines such as IL‐8, monocyte chemoattractant protein‐1 (MCP‐1), and C‐X‐C motif ligand 13 (CXCL13), all contribute partially to RA. This evidence concerns the gene CSF2 and rheumatoid arthritis.