SPP1 and systemic lupus erythematosus: Based on our data, we believe that the observed high responsiveness towards production of chemokines, such as MCP-1 and OPN, by MCs from the lupus-prone NZB/W mice (NZB/W MCs), both in the baseline (normal culture) condition and upon LPS stimulation (mimicking the LPS-induced accelerated LN model), could promote the development of the LPS-induced accelerated LN model.