The European Neuroendocrine Tumors Society (ENETS) has suggested a grading system based on the Ki-67 Labelling index (LI) in order to predict the biological behaviour of gastrenteropancreatic neuroendocrine tumors (GEP-NETs) [2]; however, such grading has not been reliably applied in PCs so far, due to the overlapping distribution of the Ki-67 LI between TCs and ACs [3]. Here, MKI67 is linked to neuroendocrine neoplasm.