Additional studies using the approaches of ANG2 blockade or Tie2 knock-down in MMTV-PyMT mammary carcinomas and RIP1-Tag2 pancreatic insulinomas suggest that the surface levels of Tie2 in TEMs or ANG2-Tie2 signaling is required for TEM interactions with adjacent tumor blood vessels and subsequent tumor vascularization [15]. This evidence concerns the gene TEK and neoplasm.