Despite the heterogeneity of our patients, univariate analysis identified age (P = 0.008), WBCs (P = 0.034), IL-21 (P = 0.005), IL-17 (P = 0.014), in addition to Th17 level (P = 0.029) as predictors for OS in patients with ALL. Here, IL21 is linked to acute lymphoblastic leukemia.