Testicular germ cell tumors (GCT) represent a highly curable malignancy predominantly affecting young men. However, survivors face long-term treatment-related complications. This study investigates whether plasma levels of protein biomarkers, including Serum Amyloid A4 (SAA4), Apolipoprotein A1 (ApoA1), Apolipoprotein E (ApoE), and Kininogen-1 (KNG1), are associated with impaired sexual function, treatment modality or cumulative cisplatin dose in GCT survivors.