Rare diseases affect some 400 million people worldwide, but no effective treatment exists for 95% of them. There’s a sense among drugmakers, says Chris Moxham, CEO and chief scientific officer of Transcripta Bio, “that the [rare disease] market is not big enough to have return on investment.” Transcripta is dramatically reducing the time and money it takes to discover drugs—not just for rare diseases, but for any drug that treats disease by changing gene expression (the process by which DNA ultimately directs cell function). The company’s Drug-Gene Atlas database shows how small molecules affect gene expression, allowing it to identify new uses for already-approved pharmaceuticals and, with the help of AI, novel candidates. In less than two years, Transcripta moved five FDA-approved drugs into single-patient studies for new indications, which otherwise might have taken five to eight years. In April, the startup closed a $10 million funding round to accelerate its work.