Scientists have developed a genetically encoded device called TimeVault that records and stores genetic information from mammalian cells for future reading[1]. The system uses engineered particles called vault particles, which capture mRNA molecules via a poly(A)-binding protein[1]. Stored genetic information remains stable in living cells for more than 7 days[1]. TimeVault enables changes in gene expression to be recorded with minimal disruption to the cell and has revealed genes active before treatment in lung cancer cells that are resistant to EGFR inhibitors[1]. The system extended mRNA lifetime more than sevenfold compared to normal decay[6]. Using TimeVault, scientists identified protective genes in drug-resistant cancer cells and then successfully treated them with another drug targeting a different gene[6]. Current limitations of the system include the ability to only bulk RNA analysis and records limited to approximately one week, which could be improved in the future with further engineering[6].