While tumors were induced in all animals inoculated with cellular DNA when the control pMSV-T24-H-ras/MSV-c-myc plasmid was co-injected, demonstrating that none of the cellular DNAs had inhibitory activity, no tumors were induced in mice that were injected with the tumor-cell DNA alone, which suggests that detecting activated oncogenes in cellular DNA might be problematic even with sensitive animal models such as the newborn CD3 epsilon mouse. Here, HRAS is linked to neoplasm.