Fig 1.

Vascularization of RIF vs. RIF-Matrigel tumors. Representative masked images of CD31-identified vasculature (A; insets of Hoechst staining). Mean (±SE) vascular area (B) and vascular density (C) for 21–22 sections (3 depths from 4–5 tumors). On individual sections, mean intervascular distance was calculated (D; horizontal line indicates median), and the coefficient of variation (E) measured to assess intratumor heterogeneity in vascular spacing (n=4–5 animals). *indicates p<0.05 for differences between RIF and RIF-Matrigel tumors.