The BCR-ABL1 test is not typically used to predict the success of hematopoietic stem cell transplantation (HSCT) in leukemia treatment. HSCT is a complex procedure with multiple factors influencing its success, including disease type, disease stage, the patient's overall health, and donor matching. While the BCR-ABL1 test provides information about the disease burden and response to treatment, predicting HSCT success involves clinical evaluation, engraftment status, graft-versus-host disease assessment, and other specific transplant criteria. The test may be part of the assessment but is not the sole predictor of HSCT outcomes.