We use different types of cell cultures (i.e. melanoma tumour cells, tumour-associated fibroblasts, endothelial cells) and serum or plasma samples in the context of melanoma, immuno- or targeted therapy or photopheresis. After clinical and biological characterisation, we perform sample preparation and subsequent mass spectrometry. These data are analysed using various bioinformatics tools and correlated at the genetic level. This is followed by functional and clinical validation.