DNAJB9 and kidney disorder: To overcome these diagnostic issues, in 2018, DNA J homolog subfamily B member 9 (DNAJB9), a heat shock protein involved in the unfolded-protein response, was identified as one of the main constitutive proteins of FGN fibrils deposits, and subsequently proposed as an innovative immunohistochemical (IHC) diagnostic marker of FGN, allowing its distinction from other kidney diseases with structured glomerular deposits [2,7,8].