On closer inspection, inflammatory biomarkers such as TNF‐a and IL‐1 have several common pro‐inflammatory properties, such as prostaglandin E2 (PGE2) production as well as the activation of collagenase (Feghali & Wright, 1997), which in cases such as rheumatoid arthritis can cause joint damage. This evidence concerns the gene TNF and rheumatoid arthritis.