IgA nephropathy is the most common inflammatory kidney disease among the glomerulonephritides. Berger and Hinglais described the disease in 1968.1 IgA nephropathy is generally considered a benign kidney disease, which is true if compared to many vasculitides, but false in view of a recent analysis of real-world data from the UK National Registry of Rare Kidney Diseases (RaDaR),2 which found that patients with IgA nephropathy had a median kidney survival time (until kidney failure, all-cause death, or end of follow-up) of only 11·4 years (95% CI 10·5–12·5).