XBP1 and rheumatoid arthritis: To assess whether increased TNFα and IL-6 levels in synovial tissue contributed to the abnormal expression of PDK1, XBP1 and ACACB in RA synovium, MH7A, a fibroblast-like synovial cell line generated from RA synovial tissue, was treated with 50 ng/mL TNFα or 10 ng/mL IL-6 for 4 or 8 hours, and the transcript levels of the three Hub genes were analyzed using qPCR.