FOS and autoimmune polyendocrinopathy: To explore the immunoregulatory mechanism of APS, the expressions of mRNAs and proteins of the key nodes (TLR4, MyD88, TRAM, TRAF-6, NF-κB and AP-1) in TLR4 signaling pathway were detected using qRT-PCR (Fig. 2A) and Western blot (Fig. 2B and C).