Tie2+ monocytes express a number of tumor-promoting genes including Mmp9, Vegfa, Cxcl12, Tlr4, Nrp1, and Pdgfb at a high level [143], and their pro-angiogenic potential could be further stimulated by EC-derived factors in the perivascular niche [144]. This evidence concerns the gene PDGFB and neoplasm.