This project investigates how the location of metastases at the time of diagnosis influences how melanoma spreads and responds to systemic therapies such as immunotherapy (anti-PD-1/CTLA-4) and targeted therapy (BRAF/MEK inhibitors). By mapping the progression of disease across different organs, we aim to uncover why certain metastatic sites, like the brain or liver, drive resistance and worse outcomes, while others may be associated with better survival. These insights will inform predictive models and guide more personalised treatment and follow-up strategies for patients with advanced melanoma