In 18 patients who did not receive systemic steroids after transplant, we observed a positive correlation between T-cell dose and CD4+ T-cell recovery at 90 days, excluding the one outlier; a patient with aplastic anemia who developed early mixed chimerism and had received the lowest T-cell dose of 90 million/kg (p < 0.02, r = 0.50; Fig. 1d). The gene discussed is CD4; the disease is idiopathic aplastic anemia.