In addition, Rullo et al. (2013) showed that increased OPN is associated with higher titer of antibodies to ds-DNA (p = 0.001) and elevated IFN-α (p = 0.02), which were shown to be important in pathogenesis and clinical manifestations of SLE (Bengtsson et al. 2000). This evidence concerns the gene SPP1 and systemic lupus erythematosus.