EmotIN-CAN is a longitudinal project that analyzes the interaction between emotional states (depression, anxiety, fatigue) and the immune response in breast cancer patients. The goal is to evaluate emotional evolution during the six months following diagnosis and its association with biological markers (cytokines, cortisol) and treatment response. The project employs an innovative translational approach, combining digital monitoring via a mobile app, clinical interviews, and gene expression analysis (RNAseq), integrating expertise from psychobiology, immunology, and oncology.