IL6 and rheumatoid arthritis: However, there were no significant differences in TB antigen-stimulated levels of IP-10, IFN-γ, TNF-α, IL-2, IL-6, IL-17A, IL-8, IL-10, or IL-13 between RA-TB patients and RA non-TB patients or non-RA TB patients (Table 2 and Fig 3B–3I).