TLR4 and arthritic joint disease: In autoimmunity, it was accepted that IL‐29 secretion was inhibited by IL‐4 stimulation on Th17 cells from psoriasis patients.12 In arthritis, the role of IL‐29 to enhance the expression of TLR4 in macrophage cell line RAW264.7 cells could be strengthened after adding LPS stimulation.