A larger toolbox of STI policy instruments and the involvement of new actors in innovation policy design and delivery are complicating the policy landscape. This raises the issues of optimising the policy mix and multi-level governance. The “silo” approach caused by thematic and vertical segmentation, which has underpinned STI policy developments, is being questioned. Significant efforts are made to integrate STI policies at different levels (regional, national, supra-national) and in different fields (research, industrial innovation, etc.).