PTPRZ1 and brain cancer: In the four brain cancer data sets, PTPRZ1 is expressed selectively above the baseline \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$r=2.0$$\end{document}r=2.0 in 0.99 (GSE89567), 0.84 (GSE70630), 0.96 (GSE102130), and 0.27 (GSE84465) proportion of cells in each cohort.