We haven't been able yet to determine in terms of genes what makes a human being a human and not another mammal.
“The older you get, the more you realize that the way you look is a reflection of how you treat yourself.”
“I am an invisible man. I am a man of substance, of flesh and bone, fiber and liquids - and I might even be said to possess a mind. I am invisible, understand, simply because people refuse to see me.”