Leukocytes are extremely cool because they are cells with a mind of their own. They are free moving with a loose connection to blood vessel walls but they can direct themselves out of the vessel to do house cleaning.

Excellent links Adam. But they posit more quandaries for the evolutionists!
To look at the Leukocyte from a skeptical evolutionary standpoint, one must ask themselves:
How did the Leukocytes develop a “mind of their own”? I ask this because it begs the question; how did the body heal itself prior to the Leukocyte? Or how did the body
rationalize the need a healing for itself prior to
reasoning (this is a question that befuddles the evolutionist)? Because, if the body didn’t have a defensive mechanism
prior to the Leukocyte,
how did the body survive?
If all of the mechanisms (and there are many) our bodies require to survive were not in place already (from the beginning), how did the body survive? Why was life not snuffed out in its infancy?
If evolution has the ability to do all the things evolutionists claim, how can it not be a
metaphysical life-force?
Guidance requires intelligence, does it not?