P53 do7

We used formalin-fixed, paraffin-embedded (FFPE) tissue for histopathologic analysis and immunohistochemical (IHC) staining. All of the FFPE tissues were stained with hematoxylin and eosin. The detailed histopathologic features were reviewed by three breast pathologists (H.L., Y.A.C., and E.Y.C.). IHC staining was performed on 4-μm sections of FFPE tissue using a Leica BOND-III system (Leica Biosystems, Wetzlar, Germany) to stain for estrogen receptor (ER; 6F11, 1:300, Novocastra, Newcastle upon Tyne, UK), progesterone receptor (clone 16, 1:1,200, Novocastra), p53 (DO7, 1:1,200, Leica Biosystems), Ki-67, (MIB1, 1:200, Dako, Carpinteria, CA), and cytokeratin 5/6 (D5/16B4, 1:100, Dako) and the Ventana BanchMark XT platform (Ventana Medical Systems Inc., Tucson, AZ) to stain for HER2 (4B5, Ventana Medical Systems Inc.) according to the manufacturers’ protocols.

Hematoxylin and Eosin (H&E) sections and all immunohistochemical stains were reviewed. BM trephines were formalin-fixed, decalcified in EDTA, and paraffin-embedded (FFPE). Immunohistochemical stains were performed using an automated immunostainer (Ventana Medical Systems, Tuscon, USA), according to the manufacturer’s protocol. The following antibodies were used: SOX11 (MRQ-58) (Medac Diagnostika, Wedel, Germany) and p53 (DO-7) (Novocastra Liquid, Leica Biosystems, Newcastle, UK). SOX11 stain was scored as negative (0%), low (1-10% positive cells) and positive (>10% positive cells). p53 was considered positive when >20% cells were strongly positive.