Relapsed and refractory acute myeloid leukemia (AML) presents one of the most formidable challenges in oncology, lacking a unified and efficient treatment strategy. Dr. Johannes Schetelig, Head of the Cell Therapy Unit at the Technical University of Dresden and Chair of the Clinical Trials Unit within the DKMS, offers invaluable insights into the complexities and evolving approaches in managing this condition. From the nuances of defining refractory AML at various stages to the critical decision-making involved in stem cell transplantation, Dr. Schetelig's expertise sheds light on current practices and future directions. This article delves into the multifaceted strategies for treating relapsed and refractory AML, focusing on patient suitability for stem cell transplantation, predictive clinical characteristics for better outcomes, and proactive measures to prevent relapse post-transplantation. 

Chronic graft-versus-host disease (cGVHD) is a clinical syndrome occurring after allogeneic hematopoietic stem cell transplantation (allo-HSCT), where the recipient’s organs are attacked by donor-derived lymphocytes during the reconstitution of the donor's immune system. This includes both classic cGVHD and overlapping syndromes and is one of the main complications of transplantation, with an incidence rate of 30% to 70%. The mechanisms behind cGVHD are complex, its clinical manifestations diverse, and the individual differences significant. The course of the disease can be prolonged and persistent; if not properly diagnosed and treated, it can severely affect the patient's quality of life and long-term survival. With the introduction of guidelines, there are now standardized diagnostic criteria and first-line treatment protocols for cGVHD, but there is still no consensus on second-line treatments. PI3Kδ inhibitors, which interfere with the proliferation and survival of lymphocytes by inhibiting the activity of the PI3Kδ enzyme and thus suppress tumor growth, have not only introduced new drugs and strategies for non-Hodgkin's lymphoma but have also shown therapeutic potential in the treatment of GVHD. At the recent 50th European Society for Blood and Marrow Transplantation (EBMT) annual meeting, a basic study from the Second Affiliated Hospital of Army Medical University was selected for an oral presentation (Abstract No: OS7-05) [1], showcasing the activity of PI3Kδ inhibitors in the treatment of cGVHD. "Oncology Frontier - Hematology Frontier" has invited Professor Qingxiao Song from The Second Affiliated Hospital of Army Medical University (Xinqiao Hospital) to interpret and comment on this research for our readers.there is still no consensus on second-line treatments. PI3Kδ inhibitors, which interfere with the proliferation and survival of lymphocytes by inhibiting the activity of the PI3Kδ enzyme and thus suppress tumor growth, have not only introduced new drugs and strategies for non-Hodgkin's lymphoma but have also shown therapeutic potential in the treatment of GVHD. At the recent 50th European Society for Blood and Marrow Transplantation (EBMT) annual meeting, a basic study from the Second Affiliated Hospital of Army Medical University was selected for an oral presentation (Abstract No: OS7-05) [1], showcasing the activity of PI3Kδ inhibitors in the treatment of cGVHD. "Oncology Frontier - Hematology Frontier" has invited Professor Qingxiao Song from The Second Affiliated Hospital of Army Medical University (Xinqiao Hospital) to interpret and comment on this research for our readers.