FN1 and systemic lupus erythematosus: It was shown that blocking the interaction between LILRB4 and FN using recombinant proteins of LILRB4 or monoclonal antibodies to LILRB4 significantly reduces the increase in pathogenic autoantibody IgG and increases the amount of protective IgM antibodies, which can be used for the treatment of SLE in BXSB/Yaa mice [37].