It is now widely accepted that innovation is a territorially embedded process, which cannot be fully understood independent of the social and institutional conditions of individual places. On the basis of these considerations, some authors identified criteria to define the geographic confines for the innovative process, introducing the concept of the local systems of innovation (LIS), defined as networks of technologically specialized and locally situated firms, institutions and research agencies. Nevertheless empirical evidences show that especially in high tech industry like life sciences, relatively few clusters are completely self-sufficient in terms of the knowledge base from which they draw suggesting that the knowledge flows that feed innovation in a cluster are often both local and global.