AbstractThe levels of soluble interleukin‐2 receptors (sIL‐2R) and tumor necrosis factor (TNF) were determined in the serum of 61 children with hematological malignancy, including 20 patients with leukemia and 16 with lymphoma in active state of malignancy, and 20 patients with leukemia and 5 with lymphoma in complete remission. In addition, serum samples from 15 healthy children were used as controls. It was found that the mean serum levels of sIL‐2R and TNF were significantly increased in active malignancy (207.0±17.1 pmol/L for sIL‐2R; 209.7±35.0 pg/mL for TNF) compared to the remission status and normal controls (P<0.001). No such difference was observed between leukemia and lymphoma groups.It was concluded that serum sIL‐2R and TNF are of potential value in the diagnosis and follow up of patients with neoplast