Ji et al. BMC Genomics 2012, 13:441 http://www.biomedcentral.com/1471-2164/13/441 Page 10 of 16 Figure 4 Heat map of metabolites. The median value of each metabolite in each treatment group was used to calculate fold-change of fasted vs. fed, insulin-neutralized (insneut) vs. fed, and insulin-neutralized vs. fasted, and then values were subjected to hierarchical clustering.