Cytogenetics of Leukemia

For many years it has been recognized that patients who apparently have the same type of leukemia have different prognoses and different responses to treatment. These differences have been thought to reflect the presence of indistinguishable diseases that superficially appear to be similar. Recent advances indicate that genetic changes in tumor cells may have a signal role in these differences. Although chromosomal changes in tumor cells have been suspected since the turn of the century, it has only recently become possible to demonstrate them. The establishment of the correct chromosome number in human beings in 1956 set the stage for . . .