RA patients also showed higher levels of acute phase reactants erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), interleukin levels (IL-6, IL-1β, TNFα), homocysteine, and leukocytes than HCs, while they displayed lower physical activity levels and presented lower haemoglobin levels than HCs. Here, IL6 is linked to rheumatoid arthritis.