TNFRSF9 and acute lymphoblastic leukemia: An increase in leukocyte TNFRSF9 level was observed in patients with ALL (range: 3.1–5.3, p < 0.05) and AML (range: 3.1–8, p < 0.05) compared to the control group (range: 3–5, p < 0.05), while plasma TNFRSF2 was elevated only in patients with ALL (range: 15.9–146.5, p < 0.05) compared to the control (range: 14–52.6) and AML patients (range: 11.5–249.2, p < 0.05) groups.