Fig. 1

Fibroblasts enhance tumor growth. a Graph shows tumor volumes at the endpoint of the xenograft study. Breast carcinoma MDA-MB-231 cells, empty-vector control (EGFP) and kinase-inactive TGFBR1 (dnTBR1), were inoculated in SCID mice (6 mice/group) alone (T) or in combination with fibroblasts (T + F). **, P < 0.01; *, P < 0.05. b Images of tumors at the endpoint of the study. Arrows indicate sites of hemorrhages. Bar size, 10 mm. c Staining of fibroblasts with antibodies to smooth-muscle actin (SMA) and rPH, prolyl 4-hydroxylase, a marker of rat fibroblasts. Images were taken at × 400 magnification, bar size, 50 μm