In a phase II study in 25 pediatric NF1 patients with recurrent, refractory, or progressive low-grade glioma, 40% of the patients had \documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$\geq 50\%$$\end{document} tumor reduction with selumetinib, and only one patient had progressive disease [31]. The gene discussed is NF1; the disease is neoplasm.