Stiffness Level of Various Tissues (IMAGE) Korea Brain Research Institute Caption The bigger the number, the harder it is. Credit Butcher et al, Nat. Rev. Cancer, 2009 Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.