Matthew Padula and collaborators have utilized Deep Visual Proteomics (DVP), combining imaging, laser isolation, and high-resolution mass spectrometry, to generate a spatial map of a rare bladder cancer tumor at the cellular level. This method enables precise proteomic profiling of individual cells within their native tissue context. The analysis identified deregulated DNA damage response proteins implicating mismatch repair deficiencies as causative. This work, leveraging technologies developed by Matthias Mann’s lab, heralds a new era of spatially-resolved tumor biology that may inform personalized cancer therapies by pinpointing critical molecular drivers within tumor microenvironments.