Graphs represent models after 1,000 cycles of validation trained with both clinico-pathological data and Oncotype DX expression data for ER, PgR and HER2 (A) or with clinico-pathological data alone (B). Error bars represent standard deviation from the mean. ER intensity, estrogen receptor staining intensity; ER score, estrogen receptor expression score (immunohistochemistry); PR intensity, progesterone receptor staining intensity; PR score, progesterone receptor expression score (immunohistochemistry); ODX ER, Oncotype DX estrogen receptor gene expression score; ODX HER2, Oncotype DX HER2 expression score; ODX PR, Oncotype DX progesterone receptor gene expression score; Tumor_arch, tumor differentiation score; Tumor_nuc_grade, tumor nuclear grade.