The Kras mutational spectra of chemically induced lung tumors in different inbred mice mimics the spectra of KRAS mutations in adenocarcinomas in smokers versus nonsmokers.
However, Ras mutational analysis demonstrated that only one of the tumors in this series, an oncocytic carcinoma with a balanced karyotype, had activating Ras mutations (at codon 13 of K-Ras).