Eli5 If the body is constantly renewing at a cellular level,why does the body reject organs or limbs from transplants?

Question

ie, if every cell is constantly replaced wouldn’t the organ eventually be replaced by your own cells that your isn’t trying to kill?

In: Biology

Answer 1

Like cells replace like cells. For example, your muscle cells are replaced with other muscle cells. So the cells of the organ are replaced with cells from itself, not cells from the host body.