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is a lovely place to explore, where visitors can stroll among the treetops nearly 60 feet above the ground, tunnel through an interactive play area shaped like a plant, or get a close-up view of piranha, poison-dart tree frogs, and baby water dragons.

By the time a cancerous tumor makes itself known, it has probably lived several lifetimes, developing on a twisted evolutionary path that seems to mock the entire process of cell division and growth. Although there is no dearth of promising research, cancer remains a mute and uncooperative subject. More than 40 years into the nation’s “war on cancer,” much remains unknown.

Six years ago this week, hundreds of researchers were awaiting the of their landmark study that focused on one thing ⎯ the human genome. In their study, the researchers described the complete sequence of human DNA, the order in which 3 billion genetics bases, or letters, appear along a strand of DNA.