developed enzyme‐activated nanoflares with ATP‐specific aptamers conjugated to AuNPs, which utilized overexpressed APE1 in cancer cells to cleave an engineered AP site, restoring ATP‐binding ability and triggering fluorescence enhancement for cancer‐specific biosensing and imaging.[206] In addition, monitoring immune cell activity in cancer immunotherapy has emerged as a new frontier. Here, APEX1 is linked to cancer.