When considering microcrystal-induced arthritides separately (N = 28), the decreases in IL-6 (Fig. 4a), IL-1β (Fig. 4b), and VEGF (Fig. 4e) were more pronounced while the variations in IL-6 (Additional file 2: Figure S2A), IL-1β (Additional file 2: Figure S2B), and VEGF (Additional file 2: Figure S2E) levels were non-significant in RA and SpA patients. This evidence concerns the gene IL6 and rheumatoid arthritis.