MKI67 and neoplasm: Tumours with TCS < 2.5 mm (Q1) showed significantly lower Ki67 levels at surgery and ∆Ki67 compared with tumours with TCS ≥ 2.5 mm (Q2, Q3 and Q4, Fig. 4), suggesting that a TCS value < 2.5 mm could be used as a good cut-off value to identify patients responding to NET.