Analysis of the Immunobiology of Acute Myeloid Leukemia Relapses After Allogeneic Hematopoietic Stem Cell Transplant (HSCT) for the Generation of Guidelines and Personalized Therapeutic Pathways

This is an observational research study — not a treatment trial — collecting samples and data from adults with acute myeloid leukemia (AML) who have relapsed after a stem cell transplant (allogeneic HSCT). The goal is to analyze the immune biology of these relapses to understand why they occur and to develop personalized treatment guidelines for this difficult situation. **You may be eligible if...** - You are an adult with AML that has relapsed after receiving a stem cell transplant (from a related or unrelated donor) - You have previously signed consent for a hematology biobank, and stored samples from your case are available - You are willing to participate and sign the study informed consent **You may NOT be eligible if...** - You are enrolled in another clinical trial that explicitly prohibits participation in additional studies This study involves sample analysis only — no experimental treatments are given. Talk to your doctor to see if this trial is right for you.