HMGA1 and cancer: The High Mobility Group AT-hook 1 (HMGA1) isoforms a and b are expressed at clearly higher levels in MBGroup3 than in other MB groups; HMGA1 is a DNA-binding protein frequently overexpressed in cancer cells where it plays a role in the control of cell growth and invasion; in MBGroup3, HMGA1 expression correlates with MYC expression and is associated with poor survival [188].