We have found evidence that the TGF\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\beta$$\end{document}β and ERBB signals that cancer and fibroblast exchange create bidirectional positive interactions that enhance the growth of both cell types. Here, EGFR is linked to cancer.