**9. Conclusions**

Since the last reviews, published more than 10 years ago now, several clinical studies, reported here, provide additional arguments that IgAN and IgAV would be the same disease. In the absence of large studies, including adults and children from different geographical part of the world, suffering from IgAN or IgAV with or without renal impairment, it is not ye<sup>t</sup> possible to conclude on their differences or similarity in terms of prognosis and sensitivity to treatment. Answering these questions gives opportunity to future clinical studies.

**Funding:** This research received no external funding.

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Acknowledgments:** I would like to thank my colleague, D. Pievani for his skillful assistance for writing and text editing, J. Verine for the renal biopsy picture, and J. Barrat for providing Figure 2.

**Conflicts of Interest:** No conflicts of interest to declare.
