CTSB and prostate cancer: SNG1005 is a brain-targeted PDC that has demonstrated promising clinical efficacy in treating brain metastases from breast cancer, and is currently in Phase 3 clinical trials.96 AEZS-108 is a PDC targeting GnRHR, which is being evaluated in trials for the treatment of proliferative fibrotic prostate cancer.96,97 Besides, an ingenious design is an intelligent ultrasound theranostic peptide-porphyrin conjugate (P18-P) that self-assembles into supramolecular structures through cathepsin B (CTSB)-triggered aggregation.