Pttg, which was first identified from rat pituitary tumour cells (Pei and Melmed, 1997), and subsequently shown to be over-expressed in human pituitary tumours (Saez et al., 1999), encodes a securin protein that plays a role in cell transformation, aneuploidy, apoptosis and tumour microenvironment communication (Vlotides et al., 2007). This evidence concerns the gene PTTG1 and pituitary tumor.