Recent technological developments have expanded and intensified the use of lanthanides in domains as diverse as renewable energy, computing, and medicine. Increasing usage of these metals raises the question of their impact on the environment and human health. However, the potential toxicity of these metal ions, and its underlying molecular mechanisms, are still little known and rarely investigated in human cell models. The goal of the PhD will be to investigate the human cells response to exposure to Ln ions, and to systematically identify the proteins involved in this response, using a set of chemical and biological tools. In particular, we want to address the following questions: which protein networks are activated or deactivated following Ln exposure? Do Ln ions affect phosphorylation of proteins? Which proteins are directly interacting with Ln ions? will thus decipher what are the key biological interactors of lanthanides, their roles in living systems and the features that enable efficient binding to metals. We expect that our findings will give insights into the toxicology of those elements and inform environmental and occupational safety policies. On the longer term, new bio-inspired strategies for their extraction, recycling, decorporation and remediation will arise from the molecular understanding of metal-life interactions, enabling a well thought-out usage of these elements to support the environmental and numerical transitions.s