Book excerpt: Recognizing the potential design complexities and ethical issues associated with clinical trials for gene therapies, the Forum on Regenerative Medicine of the National Academies of Sciences, Engineering, and Medicine held a 1-day workshop in Washington, DC, on November 13, 2019. Speakers at the workshop discussed patient recruitment and selection for gene-based clinical trials, explored how the safety of new therapies is assessed, reviewed the challenges involving dose escalation, and spoke about ethical issues such as informed consent and the role of clinicians in recommending trials as options to their patients. The workshop also included discussions of topics related to gene therapies in the context of other available and potentially curative treatments, such as bone marrow transplantation for hemoglobinopathies. This publication summarizes the presentation and discussion of the workshop.