DLL3 and metastatic neoplasm: - Surgery: Radical cystectomy for localized disease- Chemotherapy: Platinum-based regimens (etoposide and cisplatin) standard for metastatic disease- Immunotherapy: Mixed results; some trials show response, others do not- Targeted Therapy: DLL3-targeted therapies under investigation (e.g., HPN328)- ADCs: Limited efficacy; nectin-4 low expression