Transfusing AIHA patient is a challenge to the immunohematologist as it is encountered with difficulties in ABO grouping and cross matching requiring specialized serological tests such as alloadsorption or autoadsorption.[7] To better understand the risk factors, prognosis, and management of post-HSCT AIHA, we carried out a retrospective analysis of 265 allogeneic HSCTs performed at Chang Gung Children's Hospital between 1998 and 2015. This evidence concerns the gene ABO and autoimmune hemolytic anemia.