After tumor development, mice were trained in the Morris water maze to assess spatial memory, and subsequently, they received weekly injections of either saline or a combination of cyclophosphamide (CYP; 66.7 mg/kg, i.v.)and doxorubicin (DOX; 6.7 mg/kg, i.v.)for 4 weeks. The gene discussed is PPIG; the disease is neoplasm.