Which human internal organ can fully regrow even after 75% of it is removed?

While most organs form scar tissue when damaged, the liver is a master of self-repair. If up to 75% of the liver is removed, the remaining cells trigger rapid growth to restore its original mass within weeks. In mammals, this is called compensatory hyperplasia; the organ gets bigger to regain full function, proving it's the body's most resilient internal powerhouse.