to examine the relationship between altered spontaneous mutation rates and malignant characteristics of cells , two hydroxyurea-resistant chinese hamster ovary cell lines , with alterations in ribonucleotide reductase , were examined for their rates of spontaneous mutation to 6-thioguanine and ouabain resistance , tumor growth rates and their ability to form experimental lung metastases .
C0020402
resistant
C0035547
ribonucleotide reductase