In RA-FLS, LPS regulates NF-κB and AP-1 activation by inducing the formation of the TLR4/MyD88/TRAF6/c-Src complex, leading to the induced high expression of vascular cell adhesion molecule-1 (VCAM-1) and immune cell infiltration of the synovium [80]. Here, TRAF6 is linked to rheumatoid arthritis.