Moderate HER2 expression as a prognostic factor in hormone receptor positive breast cancer. - Eggemann, Holm; Ignatov, Tanja; Burger, Elke; Kantelhardt, Eva Johanna; Fettke, Franziska; Thomssen, Christoph; Costa, Serban Dan; Ignatov, Atanas (Endocrine-Related Cancer, 2015)