The biologist who tried to cure Bruce Banner, got some of his blood in an open wound, and has been waiting ever since.
Samuel Sterns is a loose end this catalogue left dangling for sixteen years. He is the scientist who corresponded with Banner as “Mr Blue”, replicated his blood, and was then forced at gunpoint to use it on Emil Blonsky.
When Blonsky becomes the Abomination the lab is destroyed, and a drop of Banner’s blood falls into an open cut on Sterns’s head. The last thing The Incredible Hulk shows of him is his skull beginning to change while he smiles. Nothing happened with that until Brave New World.