A study from Hentic et al. [98] found three well-differentiated NETs (WD-NETs) to have a Ki-67 index >20%, though few in number, these tumours had a worse survival rate than the WD-NETs with a Ki-67 index <20%, and a better survival than PDECs (five-year survival of 33% versus 6%). Here, MKI67 is linked to Wilson disease.