Case Presentation: A 36-year-old male with a history of B-cell acute lymphoblastic leukemia (ALL) treated with Hyper-CVAD with intrathecal chemotherapy and allogenic hematopoietic stem cell transplant (HSCT) from a haploidentical donor (CMV D-/R+). His ALL relapsed 8 months after transplant and he subsequently underwent pre-phase chemotherapy for future CAR T-cell therapy, developing pancytopenia. He was [...]