The present invention provides an imidazo[4,5-c]quinolin-2-one compound, or a pharmaceutically acceptable salt thereof, that inhibits both PI3K and mTOR and, therefore, is useful in the treatment of cancer.本發明提供一種咪唑并[4,5-c]喹啉-2-酮化合物或其醫藥學上可接受之鹽,其抑制PI3K及mTOR兩者且因此適用於治療癌症。