The cells in our bodies communicate with each other with structures known as transport proteins. Transport proteins allow molecules and other structures in and out of the cell. This homie got his hands on transport proteins that would allow him out of his "cell"
In organic cells there is a cell membrane that is semi permeable, it only allows very small things to pass through it (water molecules, other smaller molecules, etc). Otherwise you need an active or passive method of passing through the cell membrane. One of the ways is with transport proteins (and an energy source) which sort of act like locks. Or so what I remember from highschool biology.
The joke is that the proteins the prisoner received in the mail enable him to escape the jail by passing through the cell wall (membrane).
Supposedly, in a classic episode of Doctor Who, the Doctor calculated that there was a non-zero chance for all of the molecules in a rubber ball to align with all of the molecules in a wall in such a way as to allow the ball to pass through the wall. He then spent some time bouncing the ball off of said wall to test the theory. Perhaps something similar could be a backup plan for the guy in this comic.
How is that possible? The ball is interacting with its own atoms via the electromagnetic field, right? Providing enough of a repellant force so it doesn't phase through itself. Why would the wall be any different?
I thought this kind of thing was quantum tunneling.