Scientists just discovered a strange new DNA shape lurking in human cells

The discovery of DNA as a double helix is a hallowed story of scientific triumph—the work of four researchers merging together to solve one of science’s biggest mysteries, giving birth to what we know as the field of modern genetics. But decades later, we’re still learning that DNA is a more furiously complicated piece of biological machinery than we ever knew.

For the first time ever, scientists have just discovered a new shape of DNA lurking inside human cells. In a study published Monday in Nature Chemistry, a team of researchers from the Kinghorn Centre for Clinical Genomics at the Garvan Institute of Medical Research in Sydney describe finding DNA as a four-stranded knot-like structure—called an i-motif—in human cells, upending much of what we previously thought could and could not exist in living humans, and eliciting a slew of questions about what the role of this structure might be, if it even has one.