Yesterday I walked around Gaudi’s beautiful cathedral, Sagrada Familia, still under construction more than a century after it was started. In the vaults and columns, simple patterns and rules are played out in endless variations making beautiful, complex forms. (If you’re reading this blog, you likely thought of organogenesis instead of architecture.) Gaudi invented new techniques to plumb the limits of his craft: for instance, he made inverted models, in which weights hung from the ceiling revealed the load a column could bear.

So, persistence of vision, innovative models, and new applications of old ideas create Barcelona’s most-visited monument. But, if you’re in the right mood, there are parallels to stem cells. And of course, the field is still under construction.

What do stem cells have that Sagridia Familia does not? Epigenetics. I’ve been asking everyone what’s going to be big at this conference, and it’s not just the most common answer I’m getting, it’s practically the ONLY answer. How does a cell highlight its genome to know which genes to use? Can we intervene in this process? The stem cell community is just now learning how to figure this out.