ISG15 and systemic lupus erythematosus: To investigate type I IFN pathway activation in TMPD‐induced SLE mice, we analyzed PMs and BMDMs and demonstrated that both PMs and BMDMs from Pbld−/− mice exhibited impaired TMPD‐induced expression of Ifna, Ifnb, Isg15, Ifitm3, Mx1, and Isg20, compared with WT controls (Figure 7H,I).