All instances of the letters A, C, G, and T (representing the four nucleotides of DNA -- see trivia entry) are emphasized in almost all names of people and companies credited in the film. These letters appear in a different typeface from the rest of the name; also, in the opening credits they appear onscreen a little before the rest of the name, while in the closing credits they appear in blue instead of white.
After the credits complete, there is slow-motion footage, tinted blue, of the fingernails from the first scene hitting the pavement.
Out of all of the names of the cast and crew in the end credits, only three cast / crew members do not have the letters G A T C in their name from the word / title GATTACA.