CXCR4 and lupus nephritis: In accordance, the overexpression of CXCR4 has been demonstrated on peripheral blood B cells from active systemic lupus erythematosus (SLE) patients, especially those with lupus nephritis, a complication associated with heightened disease severity in flares-up (Wang et al, 2010; Hanaoka et al, 2015; Zhao et al, 2017).