Innovative peptide platforms now enable three transformative applications: (1) precision molecular diagnostics (e.g., 18F-PSMA-1007 for prostate cancer detection), (2) targeted therapies (e.g., BT5528 and SAR408701 targeting tumour-specific antigens), and (3) theranostic systems (e.g., RAYZ-8009 and 177Lu-FAP-2286 integrating imaging and radiotherapy). The gene discussed is FAP; the disease is neoplasm.