In the early 1980s, scientists observed an anomaly. Embedded within cell membranes, they identified ion channels with extraordinarily high conductance. These so-called "BK" (Big K, or Big Potassium) channels had roughly 10 times the unitary conductance (i.e., conductance per individual channel molecule) of other potassium channels, enabling much more efficient, rapid transport of potassium ions. And while later structural characterization explained how this happened, no one could understand why. That is, until now.