Updated project metadata. A greater understanding of cell signaling events that occur within the prostate cancer tumor microenvironment (TME), for example between cancer-associated fibroblasts (CAFs) and prostate epithelial or cancer cells, may identify novel biomarkers and more effective therapeutic strategies for this disease. To address this, we used cell-type specific labelling with amino acid precursors (CTAP) to define cell type-specific phosphoproteomic changes that occur when prostate epithelial cells are co-cultured with normal patient-derived prostate fibroblasts (NPFs) versus matched CAFs.