For literature search purposes, medical subject heading (MesH) terms, including “rheumatoid arthritis”, “monoclonal antibodies”, “JAK inhibitor”, “anti-interleukin 6”, “upadacitinib”, “ABT-494”, “rinvoq”, “baricitinib”, “LY3009104”, “INCB028050”, “sarilumab”, “REGN88”, and “Kevzara”, with “AND” and “OR” as Boolean terms, were applied into the databases to retrieve articles relevant to the objectives of this review. Here, IL6 is linked to rheumatoid arthritis.