Fibrillary glomerulonephritis (FGN) is a rare disease classically defined by glomerular deposition of Congo red–negative, randomly oriented fibrils that stain with antisera to immunoglobulins, although rare cases are Congo red positive or immunoglobulin negative.1,2 Despite the recent discovery of the biomarker DNAJB9, the pathophysiology is still enigmatic.1 Prognosis is poor and predictors of progression are older age, Scr and proteinuria levels at diagnosis, glomerular pattern (membranoproliferative vs mesangial), crescents, glomerulosclerosis, and interstitial fibrosis.