MYC and neoplasm: 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.