We demonstrate here i. that the level of renal Dnase1 mRNA expression is reflected by enzyme activity and Dnase1 protein expression, ii. the relative contribution of renal Dnase1 to total renal nuclease activity, iii. the renal location of Dnase1 protein expression and loss of Dnase1 protein expression during progression of lupus nephritis, and finally iv. the relevance of decreased renal Dnase1 for progression of human lupus nephritis. This evidence concerns the gene DNASE1 and lupus nephritis.