**9. Discussion**

IgAN is an autoimmune disease that appears to be driven by subtle dysregulations in the adaptive and innate immune systems which we have outlined. Given its vast heterogeneity in clinical presentation and prognosis between individuals and indeed geographical locations, IgAN is unlikely to represent a single disease, but rather a common histological endpoint towards which different paths can converge. Despite being described over 50 years ago, outcomes in IgAN have remained remarkably static over the past few decades. More recently however, significant advances have been made in the understanding of the disease pathogenesis, which has driven the development of new therapeutic strategies in a number of areas that we have described in this review. It is therefore likely that new treatments will be licensed for the treatment of IgAN within the next few years. It is hoped that advances in molecular techniques will allow the capability of targeting novel therapies to an individual's disease process at its various stages, with the ultimate aim of improving outcomes for those affected by this condition.

**Author Contributions:** Conceptualization, J.B and D.V.R.; writing—original draft preparation, C.K.C. and A.R.; writing—review and editing, J.B. and D.V.R. All authors have read and agreed to the published version of the manuscript.

**Funding:** Not applicable for this publication.

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

**Informed Consent Statement:** Not applicable.

**Data Availability Statement:** Not applicable.

**Conflicts of Interest:** C.K.C. has received research grants from GlaxoSmithKline and Travere Therapeutics, and personal fees from Travere Therapeutics. A.R. has no conflicts of interest to declare. J.B. has received research grants from Argenx, Calliditas Therapeutics, Chinook Therapeutics, Galapagos NV, GlaxoSmithKline, Novartis and Travere Therapeutics, and is medical/scientific advisor to Alnylam Pharmaceuticals, Argenx, Astellas Pharma, BioCryst Pharmaceuticals, Calliditas Therapeutics, Chinook Therapeutics, Dimerix, Galapagos NV, Novartis, Omeros, Travere Therapeutics, UCB, Vera Therapeutics and Visterra. D.V.R. has received gran<sup>t</sup> funding from Achilion Pharmaceuticals Inc., Reata Pharmaceuticals, Calliditas Therapeutics, Travere Therapeutics, Pfizer Inc., and Morphosys Pharmaceuticals. D.V.R. has received personal fees from Visterra, Novartis and Otsuka Pharmaceuticals, and holds equity in Reliant Glycosciences LLC.
