Dystrophic epidermolysis bullosa is a rare, genetic disease that affects the skin and other organs. People with the condition have skin that is so fragile that minor trauma can cause blistering and wounds. It is a painful condition and can have fatal consequences. Krystal Biotech is developing a gene therapy delivered as a topical gel for DEB and other skin conditions. We spoke to Krish Krishnan, CEO of Krystal Biotech, about the company’s gene therapy platform, why it uses the herpes simplex virus as a vector, and how its off-the-shelf gene therapy works.