And the reason we call it a hand is because it kind of looks like this, where this purple alpha helix is this structure here, this a dark purple region is this structure, and this green section is my thumb. And so it kind of looks like a hand. And so this pocket here that is formed as a result of this loop, this loop and this turn is basically where that calcium ion actually fits. And in fact, a single calcium or a single calmodulen can actually take up four calcium ions. And so these calmodulent proteins can actually be used by the cell to detect increase in calcium ion concentration. So if the calcium ion concentration increases to about five times of what it should be during steady state conditions, so from 100, about 500 nm, these calmodulent proteins can begin to bind those calcium ions.