We think this may have implications for many systems with migrating cells. Autoattractants can be very useful in migration, but because they work best when short-lived they will also be hard to find in experiments, and so may exist in many more systems than previously believed.

Finally, we show how in slow-moving cells (think macrophages) a decaying autoattractant can lead to a variety of different outcomes, from clumping to leader-follower, and how a close association just shy of clumping causes the best chemotaxis.

Next, we show how a decaying autoattractant can be much more robust than a broken down autoattractant.

We have the simulated immune cells migrate along a self-generated gradient, and produce an autoattractant in ratio to the attractant destroyed. First, we show that autoattractant must both be made and broken down to function and that saturable receptors lead to optimal autoattractant lifetimes.