Updated project metadata. Here, we introduce a 3D cell culture system based on a mixture of collagen I and matrigelTM amenable to stable isotope labeling by amino acids in cell culture and quantitative mass spectrometry-based proteomics analyses. We study the extra- and intracellular proteomic response of skin fibroblast isolated from healthy volunteers in comparison to cancer-associated fibroblasts (CAFs) on 3D culture conditions