I was born and studied molecular biology in Madrid. I did my PhD on homeotic genes at the laboratory of Gines Morata in the Molecular Biology Center Severo Ochoa in Madrid. After my PhD I stayed one more year in Gines Morata´s lab to start the molecular and genetic study of cell competition. I then took that project with me to do a postdoc in Zurich in the laboratory of Konrad Basler. In 2005 I started my own lab in Madrid at the Spanish National Cancer Center (CNIO) where my team and I discovered the existence of fitness fingerprints in the surface of animal cells in the context of research funded by a ERC starting grant. Since 2011 until 2016 I was a Professor and group leader at the IZB of the University of Bern, where I was awarded an ERC consolidator grant to study the molecular mechanisms of cell selection based on "fitness fingerprints" during development, cancer, ageing and neurobiology. Since 2016 I am a group leader at the Champalimaud Research Programme.