None of the SLE patient–derived serum induced CD14+ monocytes to secrete IFN-α, but their PBMCs still exhibited lower NLRP12 levels than the control PBMCs, as shown in Figure 1A. This finding suggested the existence of yet-unknown factors in addition to IFN-α and nucleic acids that are required to cause the downregulation of NLRP12 expression. This evidence concerns the gene CD14 and systemic lupus erythematosus.