We discovered uromodulin as the etiological gene for Familial Juvenile Hyperuricemic Nephropathy, GDD1 for gnathodiaphyseal dysplasiaj, and CSPG2 (Chondroitin Sulphate Proteo-Glycan 2) for Wagner syndrome. We identified SEC8L1 as the disease susceptibility gene for rheumatoid arthritis by detecting SNP in the SEC8L1 gene (P = 5.9 x 10^-6 in chi-square test). We identified SOCS2 as the disease susceptibility gene for type 2 diabetes mellitus by detecting SNP in the SOCS2 gene (P = 1.3 x 10^-4 in chi-square test). Adenoviral SOCS2 expression in islet beta cells decreased insulin secretion by 25%.

We produced transgenic mice expressing the constitutive active form of CDK4 in pancreatic islet beta cells under the insulin promoter and TGFb1 driven by the glucagon promoter in alpha cells in the transgenic mouse model. We concluded that the size of the endocrine islets is determined in vivo by the rate of G1 to S progression.

We generated F₂ progenies by inter-crossing F₁ progenies heterozygous for db between obese diabetic db mice and non-diabetic non-obese DBA2. Quantitative Trait Loci (QTL) analysis on F₂ progenies using expression QTL on chromosome 9 detected candidate disease susceptibility genes for diabetes. QTL analysis on F₂ progenies between db mice and non-diabetic non-obese C3H detected 7 modifier loci.

The knockout for dFMR1 in drosophila showed the disturbed diurnal variation, disturbed memory, and morphological abnormality of the neuron. The biochemical and genetic analyses proved that dFMR1 is involved in the RNAi molecular pathway.

We used the antigen receptor transgenic mice showing positive and negative selection in vivo. Based on the microarray analysis of immature thymocytes, we detected Immune-associated nucleotide-1 (IAN1) and IAN4 as the up-regulated genes. We used ethyl nitrosourea-induced mutagenesis in medaka and discovered mutant medaka showing the abnormal thymus organogenesis, and analyzed the gene expression representing the cell-specific expression in the cell lineage.