Minimal Residual Disease (MRD) testing is a way to look for very low levels of leukemia in the body that cannot be seen under the microscope. These test will be done in a laboratory at Dana-Farber Cancer Institute. If the MRD results are in the low range on Day 32, thre will be no change to the treatment program described above. If the MRD results are in the high range, then it will be recommended that treatment be changed.