CD4 and lobular neoplasia: IL-6 is significantly elevated in the urine of LN patients, may be associated with LN activity (147, 148), and has emerged as a potential biomarker, with IL-6 deficiency reducing macrophages, CD4+ and CD8+ lymphocytes, along with reduced renal IgG and C3 deposition and delayed LN in MRL-Faslpr mice (149).