KDR and cancer: Thrombin-mediated cleavage of PARs in cancer, blood cells, and vessel wall cells results in activation of transcription of many proangiogenic genes such as VEGF and its receptor (VEGFR), TF, MMP-2, angiopoetin-2 (Ang-2), basic fibroblast growth factor (bFGF), MAP, and PI3 kinases [120, 142, 170–173].