KISS1 and neoplasm: Based on these promising results, we subsequently attempted to analyze whether serum concentrations of Kisspeptin might reflect disease-specific clinicopathological parameters such as the TNM stage, the tumor resection status (R0 vs. R1), the histological tumor grading (G2 vs. G3), or the patients clinical performance status (ECOG 0 vs. ECOG ≥ 1).