IL6 and rheumatoid arthritis: In a similar vein, some studies have found that within the collagen-induced arthritis (CIA) model of Wistar rats, the administration of Lactobacillus casei has the potential to modulate the expression of COX-2, thereby mitigating the intensity of RA through the inhibition of the release of proinflammatory cytokines IL-6, IL-10, and TNF-α (30).