Overall, the MMTV-Hras/p53R172H/R172H mice closely resembled the MMTV-Hras/p53-/- mice with regard to age of tumor onset, tumor growth rates, tumor histopathological properties, tumor responses to doxorubicin, and gene expression profiles, while both groups were clearly distinct from the MMTV-Hras/p53+/+ mice. The gene discussed is HRAS; the disease is neoplasm.