MKI67 and breast cancer: Indeed, In1-ghrelin, but not ghrelin levels, levels were directly correlated with those of Ki-67 (a classical proliferation marker previously found to be correlated with In1-ghrelin expression in breast cancer samples [20]), and ROC-curve analysis revealed that only In1-ghrelin expression (but not native-ghrelin) could discriminate between patients with or without PCa, suggesting that In1-ghrelin merits further study as a potential novel biomarker in PCa.