mRNA, widely known from the COVID-19 vaccine, is not actually a “therapeutic agent,” but a technology that delivers the blueprint for functional proteins into the body so that induces therapeutic effects. Recently, its application has expanded to cancer and genetic disease treatments, but mRNA therapeutics have caused serious side effects such as pulmonary embolism, stroke, thrombosis, and autoimmune diseases because proteins are excessively produced all at once immediately after administration. Although technology to control the endogenous protein factory has been continuously needed, there had been no suitable solution.