Feng G, et al. - Researchers investigated expression, clinical significance, and function of COL5A1 in clear cell renal cell carcinoma (ccRCC) by analyzing 256 ccRCC tissues and paired adjacent normal renal tissues by immunohistochemistry and real-time quantitative PCR. Using siRNA, COL5A1 was downregulated. Impacts of COL5A1 silencing on cell proliferation, apoptosis, migration, invasion in vitro, and tumor growth in vivo were determined. They found COL5A1 knockdown led to significant inhibition of cell proliferation, and induced cell apoptosis, inhibited cell migration and invasion in vitro, and inhibited tumor growth in vivo. Significant associations of COL5A1 expression with overall survival of ccRCC patients and recurrence-free survival of localized ccRCC patients were also observed. COL5A1 could be a novel prognostic biomarker and a promising therapeutic target for ccRCC.