TNF and rheumatoid arthritis: This small RNA is particularly interesting because its deregulation in OA has been consistently reported in several studies; for example, in Rheumatoid arthritis (RA), which is characterized by chronic inflammation, miR-146 was found overexpressed in synovial tissue after stimulation with the inflammatory cytokine Tumor necrosis factor alpha (TNF-α) and Interleukin-1β (IL-1β) [37].