Modifying life itself has always been a point of deep fascination to me. Exchanging one letter of our biological code DNA may yield a totally different protein and, as a result, change what a cell is capable of. The field of protein engineering by genetic modification is the core theme threading itself through my scientific life. With the aim of developing therapeutic cells possessing novel functionalities for the next generation of personalized medicine, I acquired the necessary skills to achieve this. Studying the three-dimensional structures of proteins and probing their behavior with biophysical methods allowed me to develop a useful working knowledge of protein engineering. Subsequently, I applied this knowledge to the combination of engineered proteins and human cells to transit to cellular engineering and closer toward the clinical application of modified life itself.