To determine whether obese AT can activate CD8+ T cells, Nishimura cocultured CD8+ T cells isolated from the spleen with epididymal AT obtained from lean and obese mice and found that T cell proliferation was significantly induced by obese epididymal AT but only moderately induced by epididymal fat from lean mice, which indicates that the cellular environment of obese AT can activate CD8+ T cells to trigger AT inflammation and lead to a series of metabolic disorders. The gene discussed is CD8A; the disease is metabolic disease.