In 2013, researchers at Cambridge University in England uncovered a four-stranded structure inside human cells—what they call a quadruple helix or G-quadruplex. The research showed that the four-stranded DNA appeared more frequently during the so-called “s-phase,” when the cell copies its DNA just prior to dividing; it also seems to form where substantial amounts of the base guanine (G) exist. This, they believe, may be important to the study of cancers, which are usually driven by genes that mutate to increase DNA replication. If so, this may be yet another step in helping eradiate certain cancers.