Kovacs et al. (30) considered the Ki-67 LI assessment as the most reliable test to assess pituitary tumour aggression, while suggesting potential Ki-67 LI ranges similar to those used in our study, namely: 1–3% for ‘slow growing pituitary adenomas’ and >10% for ‘aggressive’ pituitary adenomas. Here, MKI67 is linked to pituitary tumor.