Thrombospondin-1-derived 4N1K peptide expression is negatively associated with malignant aggressiveness and prognosis in urothelial carcinoma of the upper urinary tract

Background Thrombospondin (TSP) is a multi-functional protein that appears to have dual roles in cancer, that is, either as a promoter or a suppressor. 4N1K is a TSP-derived peptide that has been reported to be associated with neovascularity, cell survival, and invasion. There is a little information regarding its pathological roles in human cancer tissues. Our aim was to clarify clinical significance and prognostic value of 4N1K expression in patients with urothelial carcinoma of the upper urinary tract (UC-UUT).