MYD88 and systemic lupus erythematosus: MyD88 expression was also slightly elevated in SLE PBMCs (Additional file 1 [Supplementary Figure 3c]), although the ratio of MyD88s to MyD88 indicated that the negative regulator, MyD88s, was dominantly expressed in the SLE PBMCs (Additional file 1 [Supplementary Figure 3d]).