Who IS this screaming man?

First of all, he is NOT screaming.  This is my dad.  He passed away February 2, 2006.  He has always been my biggest cheerleader and my artwork has never been complete without my Dad getting to see it.  Since he passed away in of cancer, I have been doing work about him and eventually the image seen above is the one that makes its way into most of my work.  It is at the very least, the tag on the back of my work.  When he first passed, I did a series of paintings showing the 4 stages of cancer.  This image is my stage one painting.  It shows the initial shock of receiving the news that he had lung cancer.  I have stages 2-4 as well and they show the radiation, the strong spirit shining through the battle, and the last image shows the machines taking over his bodily functions.  All they while, his eyes were piercing and aware.  He was an amazing guy.  We miss him every day.