Erratum to: Breast Cancer Res Treat DOI 10.1007/s10549-009-0487-x

In “Exposure measurement” section, sentence starting with “M4 from … 121.0 (25 eV).” should read as “M4 from m/z 223.2 to m/z 178.7 (25 eV) and m/z 137.8 (25 eV); and for M6 from m/z 207.0 to m/z 163.0 (25 eV), m/z 122.0 (25 eV), and m/z 121.0 (25 eV).”