Survival of patients with AITL according to the AITL prognostic index. OS (A) and PFS (B). This prognostic model could efficiently stratify the outcomes into 4 groups: patients with 0 or 1 risk factor (low risk, n = 31), patients with 2 risk factors (low-intermediate risk, n = 39), patients with 3 risk factors (high-intermediate risk, n = 55), and patients with 4-6 risk factors (high-risk, n = 32).