Changes in TNF/DOX sensitivity and intracellular resistant factors in a patient (case 4) who developed resistance to DOX. Leukemic cells were obtained at the pretreatment points (January 18, 1995) and posttreatment points (March 30, 1995) of chemotherapy with the regimen which includes DOX, and used for each assay as described in Materials and Methods. enTNF expression is represented as the relative value compared with that of KG-1 cells. The results shown are the mean (±SD) of three independent experiments. *P < .01; **P < .02; ***P < .05 by Student's t-test.