TNFSF10 and neoplasm: Yoo J et al. [36] also could not detect secreted TRAIL (sTRAIL) protein in mice sera after intravenous delivery of rAAV-sTRAIL via the tail vein, but they did observe a number of apoptotic tumor cells and significant inhibition of tumor growth, suggesting that TRAIL could be secreted into the body circulation and inhibit tumor formation at a distant site even at undetectable expression level.