Periostin is an extracellular matrix protein that has been known to be implicated in fibrillogenesis and cell migration, including cancer metastasis. Periostin overexpression in cancer cells and/or intervening stroma is usually related to tumor progression and poor patient outcomes in various human cancers; however, its role in urothelial carcinoma, especially upper urinary tract urothelial carcinomas (UTUCs), remains inconclusive. |