Volume regulation in leukemic and lymphoma cells in children and determination of cell lineage. 
Among normal lymphocytes, T cells can readjust their volume rapidly following initial swelling in a hypotonic medium, whereas B cells do not have this ability.  Based on this finding, we examined the volume regulation of malignant cells from 40 patients with lymphocytic and nonlymphocytic malignancies.  The T lineage cells were able to regulate their volume in response to hypotonic stress, whereas B lineage cells were not able to do so.  In contrast to lymphoid lineage cells, nonlymphocytic leukemia cells as well as undifferentiated cells did not show a consistent tendency in their volume regulation.  These results showed that the difference in the ability to regulate cell volume in response to hypotonic stress is available as a marker for identifying the cellular lineage of lymphoid malignancies.