The April issue of Translational Research examines the progress and outlook of gene therapy research, with a specific focus on the clinical applicability of gene therapy today. Research articles included in the special issue highlight current studies that, after decades of trial and error, may provide evidence for a clear path of treatment and cure for many diseases. There are more than 1,800 genetic disorders known in humans, and only a small fraction of these can be treated and even fewer cured. Some of these disorders are exceedingly rare, others more common. The approach of gene therapy however may be applicable to all.