The first<unk> was constructed by Hidalgo et al. (2009) to help understand the origins of many diseases and the links between them. Hidalgo et al. (2009) defined diseases as specific sets of phenotypes that affect one or several physiological systems, and compiled data on pairwise comorbidity correlations for more than 10,000 diseases reconstructed from over 30 million medical records. Hidalgo et al. (2009) presented their data in the form of a<unk>  with diseases as the nodes and comorbidity correlations as the links. Intuitively, the<unk> (PDN) can be seen as a map of the<unk>  space whose structure can contribute to the understanding of disease progression.
Phenotypic disease network 
Demographic surveillance system
Human disease network
Gain-of-function research
Disease registry
Cognitive epidemiology
Computational epidemiology
EFAR System Model