S1 Supporting Information A Double Photocage Strategy to Construct Light‐ Controllable and Spatiotemporally Trackable Cathepsin B Activity‐Based Probes Hsuan‐Min Hung a and Tsung‐Shing Andrew Wang a, * a Department of Chemistry, National Taiwan University, Taipei, 10617, Taiwan (R.O.C.) *Corresponding author: wangts@ntu.edu.tw