We found high circulating anti-nephrin autoantibody levels (1) at the time of exacerbating nephrotic syndrome and low autoantibody levels at the time of partial remission (Figure 1A, red line), illustrating the strong association of anti-nephrin autoantibodies with disease activity in patients with anti-nephrin–associated podocytopathy. This evidence concerns the gene NPHS1 and nephrotic syndrome.