IL15 and systemic lupus erythematosus: IL-15 enhances the expression of CD54 on NK cells from both SLE patients (27.4 ± 2.8% versus 18.2 ± 2.2%, p < 0.001) and controls (28.2 ± 2.9% versus 14.3 ± 2.5%, p = 0.002), respectively.