Recently, a similar approach was used by Li and coworkers to deliver the most optimized prime editing system, referred to as PE5max, to human HSCs ex vivo. By utilizing helper-dependent adenovirus (HDAd5/35++), the authors were able to achieve 3.4% prime editing of a SCD-causing HBB-variant in CD34+ HSPCs from healthy donors and 4.6% in CD34+ cells derived from SCD-patients (Li et al., 2023). The gene discussed is CD34; the disease is Schnyder corneal dystrophy.