When rare diseases are taken together, they’re not all that rare. Their underlying genes provide biological insights that drive therapeutic advances and often shed light on more common disorders. Thanks to advances in genomics and bioinformatics, growing interest from pharma and a burgeoning citizen science movement, rare disease is poised to rock biomedicine. This Storify recaps a Twitter chat hosted by the NIH (#NIHchat) ahead of Rare Disease Day on February 29. People shared statistics, great examples of rare disease science, directories of diseases/disease organizations and tools for patients, clinicians and researchers.