Commentary on Circulating microRNAs as stable blood-based markers for cancer detection: Mitchell PS, Parkin RK, Kroh EM, Fritz BR, Wyman SK, Pogosova-Agadjanyan EL, Peterson A, Noteboom J, O’Briant KC, Allen A, Lin DW, Urban N, Drescher CW, Knudsen, Stirewalt DL, Gentleman R, Vessella RL, Nelson PS, Martin DB, Tewari M, Divisions of Human Biology, Clinical Research, and Public Health Services, Fred Hutchinson Cancer Research Center, Seattle, WA