Microarray analysis of renal macrophages in NZB/W mice (https://www.ncbi.nlm.nih.gov/geo/) suggested that CTSB in the lupus nephritis stage was higher than that in the pre-lupus nephritis stage, but decreased after remission, suggesting that CTSB is involved in the damage of lupus kidney tissue (DataSet: GDS4194). Here, CTSB is linked to lupus nephritis.