IFNAR1 and systemic lupus erythematosus: To further investigate whether the IFN-α/IFNAR pathway also plays a critical role in the induction of NKG2DLs ULBPs on human Treg cells, we measured IFN-α in SLE patients’ serum and IFNAR expression on Treg cells, it was found that IFN-α levels (Fig. 5C; P < 0.0001) and IFNAR1/R2 expression in SLE patients were remarkably increased compared with HCs (Fig. 5D; IFNAR1: P = 0.0090 and IFNAR2: P < 0.0001).