CCN2 and pulmonary hypertension, primary, 1: Growth factors such as connective tissue growth factor (CTGF), platelet derived growth factor, fibroblast growth factor, and transforming growth factor - beta (TGF-\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{upgreek}\usepackage{mathrsfs}\setlength{\oddsidemargin}{-69pt}\begin{document}$ \beta $\end{document}) are more prevalent in fibrotic tissues and are associated with PHT enlargement.