Anti-CD137 has a therapeutic effect in mice with more severe cutaneous GVHD. (A) Anti-CD137 (200 μg per mouse) was administered one time 56 days after induction of cGVHD. Fifty-four days later, clinical scores for each mouse were evaluated. Data were combined from 2 experiments (n = 14 for control Ig group; n = 15 for anti-CD137 group). (A) Changes of mean clinical scores. *P < .05, between the 2 groups. (B) Changes of body weight. (C) Comparison of the percentage of mice with ulcers between day 56 and day 110 after disease induction. (D) Gross observation of the skin lesions in the posterior neck area. The experiment was repeated and similar results were obtained.