Correction: EpCAM-Independent Enrichment of Circulating Tumor Cells in Metastatic Breast Cancer. - Helen Schneck; Berthold Gierke; Frauke Uppenkamp; Bianca Behrens; Dieter Niederacher; Nikolas H Stoecklein; Markus F Templin; Michael Pawlak; Tanja Fehm; Hans Neubauer; Disseminated Cancer Cell Network (DCC Net) Duesseldorf (PLoS ONE, 2016)