Twenty-eight healthy and forty-six children with malignancy admitted to the Pediatrics Oncology Clinic and Outpatient Clinic of Dicle University, Medical Faculty, Department of Pediatrics in 1989-1990 were included into this study. The children under investigation were divided into three groups. Group 1 consisted of 28 healthy children. Twenty-eight children with newly diagnosed malignant disease, before the start of treatment, formed Group 2. Group 3 consisted of eight of these 28 children together with 18 other children with malignancy in complete remission.