I started my research in pharmacokinetics at Tokyo University and extended to PK/PD until postdoctoral research at Stanford University. After coming back to Tokushima University, I changed my subject to DDS, where I found an interesting research area “controlled intracellular trafficking”. It was exciting to analyze a fate of endocytosed liposomes and control their fate by enhancing endosomal escape and nuclear delivery. Since 1999, I made a new laboratory at Hokkaido University, where we concentrated to develop the most efficient as well as safe delivery system which can control not only biodistribution but also intracellular trafficking of siRNA/mRNA/pDNA named as “MEND”. Unexpected pathway to clinical translation will also be described.