REN and nephrotic syndrome: A 76-year-old man with a history of hypertension and UV-treated cutaneous mycosis fungoid was diagnosed with membranous nephropathy (MN) after receiving the BNT162b2 vaccine, and he was treated symptomatically at first, with dietary changes and renin-angiotensin system blocking, which resulted in partial nephrotic syndrome control; after the second mRNA-1273 vaccination, his oedema worsened, leading to the first report of post-vaccination MN, with the authors concluding that mRNA vaccines may have a role in MN exacerbations [110].