Mark Thomas, MD, Royal Perth Hospital, Perth, Australia, discusses some of the key challenges associated with treating patients with gene therapies. Given the increased risk of infection and malignancy in patients receiving immunosuppression, he highlights the importance of high levels of hematological expertise when providing gene therapies to patients. In order to avoid toxicity in patients, it is necessary to follow strict protocols, obtain high-quality, objective evidence of treatment efficacy and offer meticulous care. This interview took place during the American Society for Cell & Gene Therapy 24th Annual Meeting 2021.