As the global life expectancy increases, so do cancer cases worldwide. Therefore, conquering cancer is one of the most important issues for human beings. Most of the anticancer drugs currently in wide clinical use have serious side effects because they act not only on cancer cells but also on normal cells. Hence, it is key to develop anticancer agents with selective cytotoxicity against cancer cells to reduce the side effects of anticancer agents. Therefore, the development of anticancer metal complexes to exert cancer-cell selective cytotoxicity is important to suppress the side-effects. Here, I present two strategies for cancer-cell-selective cytotoxicity of dicopper complexes. One is mitochondrial DNA targeting dicopper complex,1 and another is ER and Golgi apparatus targeting dicopper complex.2