However, it is important to mention that the TMA we analyzed did not contain superficial papillary tumors (Ta) but only T1 tumors, which are low grade and not muscle-invasive but have penetrated the basement membrane [2], suggesting that progranulin expression might identify low grade tumors likely to progress to the muscle-invasive stage of urothelial carcinoma. The gene discussed is GRN; the disease is urothelial carcinoma.