IL6 and rheumatoid arthritis: Kupffer cells may also release a number of pro-inflammatory cytokines including IL-1, IL-6, IL-7, IL-17, and TNF-α [13, 21, 57], which are markedly involved in the development of several autoimmune diseases such as rheumatoid arthritis, experimental autoimmune encephalitis, or Crohn's disease, as well as in the development of inflammatory responses [58].