Enzymes play critical roles in health and disease. In cancer, enzymes called proteases help tumor cells escape and invade by degrading the surrounding tissue matrix. In order to understand how proteases aid in cancer progression, it’s important to be able to visualize where these enzymes are active. The Bhatia Lab has developed chemical probes that can measure and localize protease activity within tissue sections. When we used one of these probes (shown in red) on an array of biopsy samples, we found that it was able to light up the prostate cancer samples, but not the healthy prostate samples. These activity probes could be used to reveal new insights into how proteases contribute to cancer and enable new ways to detect and target this devastating disease.