To provide methods for enhancing tumor engraftment and methods for producing cancer stem cells, in laboratory animals.SOLUTION: Provided is a method of testing for efficacy of a potential drug agent against cancerous cells in a non-human mammal, including generating the cancer cells in a non-human mammal； contacting the cancer cells with a potential drug agent by administering the potential drug agent to the non-human mammal； and measuring effect of the potential drug agent on the cancer cells, the reduction of number of cancer cells in the mammal being indicative of effectiveness of the potential drug agent against cancerous cells.SELECTED DRAWING: None【課題】実験動物での腫瘍の生着を増強する方法、及び癌幹細胞を作る方法の提供。【解決手段】非ヒト哺乳動物での癌細胞の生成、非ヒト哺乳動物への潜在的な薬剤の投与により潜在的な薬剤と癌細胞をコンタクトさせること、そして癌細胞での潜在的な薬剤の効果を測定することであって、哺乳動物での癌細胞の数の減少は癌細胞に対する該潜在的な薬剤の有効性を示す、非ヒト哺乳動物での癌細胞に対する潜在的な薬剤の効能についてのテスト方法。【選択図】なし
