By sequencing human DNA, scientists were able to glean new information about genes and how they are expressed. Yet there were hints that something else might be controlling which genes are turned on and off, said Jean-Pierre Issa, director of Temple’s Fels Institute for Cancer Research. “When the human genome was sequenced, some scientists were saying, ‘That's the end. We're going to understand every disease. We're going to understand every behavior.’” Issa said. “And it turns out, we didn't, because the sequence of the DNA isn't enough to explain behavior. It isn't enough to explain diseases.”