HMGA2 and pituitary gland adenoma: Moreover, HMGA1 or HMGA2 overexpression is able to transform mouse and rat fibroblasts (Fedele et al., 1998; Fedele et al., 2001), and transgenic mice overexpressing either HMGA1 or HMGA2 develop haematopoietic malignancies and pituitary adenomas (Battista et al., 1999; Arlotta et al., 2000; Fedele et al., 2002; Fedele et al., 2005; Zaidi et al., 2006).