Integrated network systems and evolutionary developmental endocrinology.

Endocrine system has been considered to be a linear one, but the 'real world endocrine system' is a complex system, which is difficult to investigate using conventional strategies, such as single nucleotide polymorphism, genome-wide analysis, or gene targeting in animals. Here we propose a new strategy to comprehend the endocrine system as a complex network system. We introduced several novel concepts, such as complex system, network analysis, systems biology and evolutionary medicine, into the comprehension of endocrine system as a whole complex network system. This system is considered to be a scale-free network with key molecules such as acetyl CoA, NAD or ATP as 'hubs'. This system is robust against simple mutations, but various complex diseases may attack hubs. The system is also 'fractals', since there exist similar network systems among cells, proteins, and transcription factors in the lower levels, and there are similar ones among disease and social network in the higher levels. We propose to call this model 'Integrated Network Systems and Evolutionary DEvelopmental ENdocrinology (INS-EDEN)'. This novel framework will facilitate us to develop a new approach for understanding and treatment of various complex diseases related to endocrinology, and identify a unified theory of complex diseases.