Thus, Ktrans may be interpreted as tumor blood flow or vascular permeability, depending on whether the underlying tumor condition is flow‐limited or permeability‐limited.(18) In this study, the increased numbers of blood vessels counted from CD31 stain images indicate increased blood flow of contrast agent or increased permeability surface area in the PNA and the VTA of VX2 tumors, reflecting increased Ktrans value in DCE‐MRI data, in turn showing positive correlations between MVD and Ktrans values. This evidence concerns the gene PECAM1 and neoplasm.