This study aimed to investigate the relationship between plasma membrane uPAR expression and blood plasma suPAR levels in patients with SLE and healthy controls, as well as to examine the effects of immune activation with tumor necrosis factor (TNF) and IFN-α (a key cytokine in SLE) on uPAR expression and suPAR levels. Here, IFNA1 is linked to systemic lupus erythematosus.