It is becoming increasingly evident that Alzheimer's disease cannot be considered as the outcome of a single pathway, but rather we should view it as a system, that is, a network of interactions between large numbers of different protein molecules. In the last few years, probably because of the inherent limitations of traditional methods and because of the great increase in availability of sequencing data, this type of approach is being used more and more. In the following, we will discuss what constitutes a "network approach," what are its pros and cons, a number of recent case studies and finally what are the future perspectives of this type of analysis.