Using tissue grown from a patient's own cells helps ... "Pretty much I was able to live a normal life after," he says. He underwent surgery 17 times before he was 13, but hasn't had to since.

Inside every tissue, cells are constantly replenishing ... However, glial cells in the brain continue to divide throughout a mammal's adult life. Mammalian epithelial cells also turn over ...

Cells. Tissues. Organs. Organ systems. And the organism itself. Cells are the building blocks of life. Tissue is made when specialised cells with the same function group together. For example ...