PGF and neoplasm: As expected, bevacizumab had a significant impact on tumor vascularity, specifically on vascular permeability, as measured by decreased contrast enhancement, decreased FLAIR hyperintensity, decreased ADC, and decreased Ktrans.23 In addition, consistent with published reports, bevacizumab changed known pharmacodynamic biomarkers such as PlGF, VEGF, and Ang2.13 Thus, bevacizumab treatment showed vascular biological effects in recurrent GBM patients.