Anti-PDGFRβ antibody 2C5 inhibited growth of Farage xenografts in SCID mice. (A) Tumor growth curves based on tumor volumes (mm³) for PBS or hIgG control (black squares), imatinib (red circles), and 2C5 (blue triangles) treatments. (B) Tumor weight (g) at the time of tissue harvest comparing 2C5 (blue) vs imatinib (red) vs control (black). Inset depicts gross morphology of the resected tumor xenografts treated with (1) control, (2) imatinib, and (3) 2C5. (C) Staining of endothelial cells (CD31, red) and pericytes (NG2, green) in Farage xenografts treated with (1) control, (2) imatinib, and (3) 2C5. (4) NG2⁺ pericytic density and (5) CD31⁺ endothelial density were normalized to their respective controls. (D) Confocal analysis of pericytes in Farage tumors treated with (1) control, (2) imatinib, and (3) 2C5. Blue marks functional vascular flow by isolectin staining; red outlines NG2⁺ pericytes; and green stains CD68⁺ myelomonocytic cells. White arrows indicate perivascular CD68⁺ cells in close association with microvessels. *P < .05 compared with control. Scale bar, 50 μm.