Objective Divided orbital fibroblasts from patients with thyroid-associated ophthalmopathy (TAO) into CD90＋ and CD90－ subsets respect to surface CD90 expression, then determined whether CD90＋ and/or CD90－ fibroblasts were capable of differentiating into lipofibroblasts. Methods Fibroblasts subset separation into CD90＋ and CD90－ subsets was accomplished by three to four rounds of magnetic bead selection, then treated with ３-isobutyl-1-lmethylxanthine (IBMX), insulin and dexamethasone which was an known inducer of the lipofibroblastic phenotype, then the cells were observed every day to find Lipid droplets. Oil red O staining were conducted at 5 d, 10 d, 15 d, 20 d and 25 d after inducing. The percent of lipofibroblasts were calculated. Results The ratio in fibroblast derived from extraocular muscles of differentiating into lipofibroblast is less than from connective/adipose tissue (P＋ fibroblast is less than CD90－ fibroblast (P＋ cells derived from extraocular miscles could not be induced to differentiate into lipofibroblast. The ratio in CD90－ fibroblast from connective/adipose tissue is highest (P－ connective/adipose tissue.
