We found that IL-17 and PDGF significantly increased the GLS1 mRNA expression in RA-FLS, while lipopolysaccharide (LPS), tumor necrosis factor (TNF)-α, IL-1β, or IL-6 and soluble IL-6 receptor (sIL-6R) did not (Fig. 4c). Here, IL1B is linked to rheumatoid arthritis.