TGFB1 and central nervous system cancer: Production of TGF-β is proportional to the size of glioma cell population, at the rate \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$b_{1}$$\end{document}b1.