Among these 19 266 genes, 333 had CN/CS values much greater than one (\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym}\usepackage{amsfonts}\usepackage{amssymb}\usepackage{amsbsy}\usepackage{upgreek}\usepackage{mathrsfs}\setlength{\oddsidemargin}{-69pt}\begin{document}${\chi}^2$\end{document} test, P < .05), of which 29.1% were known driver genes (e.g. 12.44 for TP53, 17.76 for KRAS and 23.80 for IDH1), showing that cancer-associated genes were notably enriched in genes subjected to positive selection (hypergeometric test, P = 3.99 × 10−26). This evidence concerns the gene KRAS and cancer.