Ki67 indices of more than 20% are very rare, and some metastasizing pituitary carcinomas show Ki67 indices of 0–16% [19] or 0 to 22% [18]; PitNET G3 as defined by a Ki-67 index of more than 20% should be very rare. The gene discussed is MKI67; the disease is pituitary adenocarcinoma.