This is the last phase. The cells are bombarded by greasy solar atoms which forces the body to react to protect itself. That means growing skin.
10 seconds sound clip from the The Fifth Element movie soundboard.
You can hear this line at 00:26:38 in the Blu-ray version of the movie.
Quote context
[...]
- The cell is, for lack of a better word, perfect.
- Okay, go ahead. But Mr. Perfect better be polite. Otherwise, I turn him into cat food.
- Ten seconds to ultraviolet protection.
[...]