The aim of the present study is to identify and validate molecular and clinical biomarkers of therapy outcome in metastatic melanoma. Clinical and molecular parameters of melanoma patients and their tumors will be collected in an online-based registry (ADOREG), and thereafter correlated with the outcome of subsequent systemic therapies in terms of progression-free survival, overall survival, and treatment response. Systemic therapies will include all types of currently used regimens (kinase inhibitors, immune checkpoint inhibitors, chemotherapy). FFPE tissue samples will comprise different time points (primary tumors versus metastases) as well as tumor sites (lymph node versus organ metastases) to identify potential differences in the predictive value of these materials. The anticipated results from these analyses are of essential importance for future patient selection for individualized therapy strategies.