Biomarkers analysis
As candidate tissue biomarker analyses, immunohistochemistry (IHC) for pERK (Cell Signaling, #4376, dilution 1:200), VEGF (BD Pharmingen, #555036, dilution 1:3200), neuropilin (Santa Cruz, sc‐5307, dilution 1:50), PDGFβ (Bioworld, BS1290, dilution 1:400), and HER2 (Roche Diagnostics, clone 4B5) were performed on 5 μm sections of paraffin‐embedded tissue. Representative figures are presented in Figure In addition, as candidate plasma biomarker analyses, circulating soluble proteins including sVEGFR1 (eBioscience, CA), sVEGFR2 (eBioscience), sVEGFR3 (eBioscience), VEGF‐A (eBioscience), VEGF (Invitrogen, MA), bFGF (Invitrogen), TIE1 (RayBiotech, GA), and PDGFRβ (RayBiotech) were measured by enzyme‐linked immunosorbent assay at baseline according to the manufacturers' instructions. High and low cut‐off values for these biomarkers were defined with respect to the sample median.