NOS2 and systemic lupus erythematosus: Considering the established role of inflammatory cytokines in arthritis pathology [38], to understand the impact of SLE on inflammatory responses in the femoral heads of MRL/lpr and MRL/MpJ mice, we quantified the expression levels of inflammatory cytokines and enzymes, including IL‐1β, IL‐18, IL‐6, TNF‐α, iNOS and COX‐2 and found significantly elevated levels of IL‐1β and IL‐18 in MRL/lpr mice, showing approximately 5.1‐fold and 3.3‐fold increases, respectively, compared to MRL/MpJ controls (Figure 3A,B), indicating heightened inflammatory activity.