PTTG1 and pituitary tumor: Tumour markers such as securin or pituitary tumour–transforming gene (PTTG1)9 and the Ki67 proliferation marker10 can be evaluated from the tumour, as well as several receptors of central and hypothalamic hormones such as somatostatin (sst), dopamine (DRD), ghrelin (GHSR1a) or vasopressin (AVPR1b) receptors11–16.