Interestingly, the findings of this study suggest that the regiondependent changes in proteoglycan and collagen content do not fully explain the order of magnitude differences found in compressive moduli across the osteochondral interface. Given that a positive correlation also exists between mineralization and indentation modulus in mature human calcified cartilage and subchondral bone samples,(65) it is more likely that the exponential increase in mineral content significantly enhances calcified cartilage mechanical properties. Moreover, the role of GAG- and collagen-mineral interactions may also be important for engineering the mechanics of calcified cartilage and will be investigated in future studies