In terms of regulating RA, circRNA pituitary tumor-transforming 1 interacting protein (circ-PTTG1IP) regulates toll-like receptor 4 (TLR4), an upstream regulator of the nuclear factor-kappa B (NF-κB), by directly binding to miR-671-5p. The gene discussed is NFKB1; the disease is rheumatoid arthritis.