VEGFA and neoplasm: When the volume of the primary tumor exceeds a threshold (\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\sim$$\end{document}∼ 1 mm3)30, its central cells become deficient in oxygen (hypoxic state); in response, the tumor and the cells surrounding secrete a variety of chemotactic and morphogenic tumor angiogenesis factors (TAFs) such as vascular endothelial growth factor (VEGF)31.