The immune system is a mechanism by which an organism differentiates between “self” (its own tissues) and “non-self” (everything else) and protects against non-self.
- Cancer cells originate as “self,” but as they convert from normal cells into cancer cells, they develop new and different proteins or peptides on their cell surface
- These proteins or peptides, known as “antigens,” can trigger immune cell activity, and indeed, the immune system is constantly engaged in detecting and eliminating cancer cells
- It is estimated that thousands of these abnormal cells are discovered and eliminated every day in healthy people
These activities, known as immune surveillance, kill cancer cells and help prevent tumor growth.