The year 2016 was an exciting one for the field, with several notable successes outweighing a few setbacks. As the number of patients treated successfully (and safely) with gene therapy grows, the totality of evidence points to a robust platform with utility in orphan/ultra-orphan diseases as well as broader indications, and with hopefully increasing predictability of results. This year promises to feature more patients treated, more clinical data, and more gene therapy products in registration-enabling studies. For the field to continue to advance and mature into the next great drug delivery platform, a few unsolved and remaining questions need to be addressed, including the business model for cures, a broader safety/efficacy profile once more patients are treated, optimization of delivery (including next-generation approaches), and greater understanding of the impact of competitive dynamics. In this report, we detail the success and setbacks of 2016 and highlight the unanswered questions-and how the answers may shape the field in the years ahead.