We also confirmed the importance of C3 standing > +1 as an adverse prognostic factor for renal survival in children but in our study, the endpoint was GFR < 90 mL/min, and thus we demonstrated the prognostic significance of C3 deposits for CKD from stage G2 onwards, which is a novel finding, and these observations were made in children, which also contrasts to the conclusions from the studies in adult patients with IgAN [20]. Here, C3 is linked to chronic kidney disease.