IL6 and rheumatoid arthritis: The proinflammatory cytokines such as IL-1β, IL-6, TNF, CXCL9, CXCL10, and IFN-γ participate in the pathology of several chronic inflammatory diseases including rheumatoid arthritis (Pandya et al. 2017), coronary diseases (Hansson 2005), cerebral malaria (Rudin et al. 1997), tegumentary leishmaniasis (Oliveira et al. 2014), and Chagas diseases (Gomes et al. 2003; Poveda et al. 2014).