Testicular germ cell cancer represents the most frequent solid neoplasm in young men aged 20-40 years. Depending on the prognosis according to the IGCCCG classification, the treatment of choice for advanced germ cell tumors consists in three to four cycles of bleomycin, etoposide, and cisplatin (BEP) in accordance with the current European Consensus Guidelines. Although residual tumor resection (RTR) adheres to guidelines as the treatment for residual metastatic lesions, numerous questions remain unresolved, which we intend to systematically answer within the scope of our research group by conducting prospective/retrospective and clinical/molecular investigations in cooperation with national and international project groups.