In one clinical trial (NCT03164135), a patient was successfully treated for acute lymphoid leukemia (ALL) with a CRISPR-Cas9 CCR5-ablated HSPC transplant, achieving engraftment and remission, but the patient’s HIV was not cured, with the percent of lymphocytes maintaining the CCR5 KO being ∼5% and HIV rebounding after ATI (Freen-van Heeren, 2022; Xu et al., 2019). Here, CCR5 is linked to acute lymphoblastic leukemia.