Although no significant difference was found for T-cell compartments at BOS diagnosis or several months beforehand, an increase in the CD4+CD25hiFoxP3+ T-cell sub-population was identified in patients with BOS at 1 and 6 months after transplantation (3.39 ± 0.40% vs. 1.67 ± 0.22% in STA, p < 0.001). The gene discussed is CD4; the disease is Buschke-Ollendorff syndrome.