Erel Joffe, MD, MSc, Tel Aviv Medical Center, Tel Aviv, Israel, and Memorial Sloan Kettering Cancer Center, New York, NY, comments on the role of the immune microenvironment in post-transplant lymphoproliferative disorder (PTLD), focusing on the impact of tumor-infiltrating lymphocytes (TILs) and T follicular helper cells (Tfh) on the disease. This interview took place at the European Hematology Association (EHA) Congress 2022 held in Vienna, Austria.