New strategies for gene identification have emerged. One source of novel intermediate phenotype with the utilization of microarray technology has provided valuable information on mRNA expression from thousands of genes in tissues of interest. cDNA microarray analysis for the study of obesity was first reported by Soukas et al. in 2000, using approximately 6,500 murine genes in pairs of adipose tissues in ob/ob mice and wild-type lean mice [93]. This was followed by many subsequent studies. More than 30 microarray approaches have been exploited in assessing the changes in gene expression in the adipose tissue, liver, hypothalamus, skeletal muscles, small intestines, and kidneys of lean and obese animals and human subjects. The data obtained from these genomic investigations have provided a wealth of information about obesity-specific gene profiles. The overexpression of genes related to inflammation, immune response, adhesion molecules, and lipid metabolism is a major characteristic of white adipose tissue, while the overexpression of the genes related to lipid metabolism, adipocyte differentiation, defense, and stress responses, is noticeable in the nonalcoholic fatty liver of obese rodents [94]. The hepatic-gene expression
