The effect of residual ATG exposure on CD4⁺ IR after CBT and BMT. (A-B) Residual ATG exposure affects CD4⁺ T-cell reconstitution (defined as ≥50 × 10⁶ CD4⁺ T-cells/L in 2 consecutive measurements after HCT) more in CB recipients (A; n = 155, P < .001) than in BM/PB recipients (B; n = 120, P = .74). (C) When ATG exposure is low, CD4⁺ IR is faster after CBT compared with BMT (P = .018). P values are for comparisons among all 4 groups (multivariate log-rank test), with correction for covariates.