IL6R and rheumatoid arthritis: Moreover, IL-6 is a key pro-inflammatory mediator in the pathogenesis of chronic bone consuming diseases, such as rheumatoid arthritis, and it plays the role of a drug target for the main anti-arthritic agents, such as monoclonal antibodies neutralizing either IL-6, or the specific receptor IL-6R [51], and small molecules interfering with IL-6 signaling (e.g., JAK inhibitors).