This study aims to develop and validate mathematical models for understanding the various phenomena in the human species. Among various features, we focus on molecular-level interaction in the metabolic system. We will model metabolic pathways and conduct computational simulations. The simulated dynamic changes of metabolites are compared with the experimental results using an organ chip, e.g. liver chip (A02). Subsequently, various chips, e.g. liver and kidney chips, will be connected and their interactions will be analyzed (A03). These integrated approaches enable us to understand the interaction of various organs. The detailed intervention and observations which were limited by using animal and human experiments will be realized. Through this framework, we try to understand why our body has such a complicated mechanism.