Bruce Banner was a thin, bespectacled physicist working for the United States government on defense projects in the wake of World War One. A lifetime smoker who also experimented with radioactive materials, Bruce was diagnosed with lung cancer. Rather than await death, he began working on an experimental serum based on gamma radiation, which he theorized could regenerate dead cells and provide them with greatly boosted strength and vitality. He envisioned a Super Solder Serum, one that would make U.S. soldiers stronger, faster, more resilient, and capable of healing themselves. Injecting himself with the formula and then furthering the treatment by dousing himself in gamma radiation, Banner instead transmuted into a terrible, nearly mindless grey-green monster whose first act was to destroy the lab, spilling chemicals and causing an explosion the destroyed not only the evidence, but all of Banner's notes as well.