This concluding chapter draws together the insights from preceding chapters, through examples of ways in which the integration of molecular data with traditional epidemiology methods has uniquely contributed to our understanding of the epidemiology of infectious diseases. The central focus of this chapter lies on how molecular epidemiology has been used to address key questions with public health implications, namely the origins of pathogens, patterns of infection spread, identification of infection sources, and the impact of genetic variation on disease manifestation and prevention efforts. The chapter illustrates the power of the synergy of molecular and traditional epidemiological data through historical and contemporary examples where molecular epidemiology has been successfully applied to tackle these questions and provided genuinely novel perspectives. Finally, we examine challenges inherent to the field, provide an overview of its evolving landscape and an outlook on future directions.