TNFSF11 and systemic lupus erythematosus: Serum RANKL concentrations and RANKL/OPG Ratios in SLE group were significantly higher than that in control group respectively (*P < 0.05), while the serum concentrations of OPG and 25(OH) VitD3 were significantly lower than those in control group (*P < 0.05), the difference was statistically significant (Table 2, Fig. 1).