On day 19, the average volume of control vehicle-treated WT tumors was 2559±797 mm3, doxorubicin treated WT tumor was 2099±529 mm3 (18% inhibition compared to control vehicle -treated WT tumors), control vehicle -treated PTTG1−/− tumors was 1416±585 mm3 and doxorubicin treated PTTG1−/− tumors was 329±263 mm3, indicating a 77% inhibition (p<0.001) when compared to control vehicle-treated PTTG1−/− tumors. The gene discussed is PTTG1; the disease is neoplasm.