>> reporter: john cornic has als, better known as lou gehrig's disease. the nerve cells in the bin and sprain that control muscle movement, destroyed. when the brain can no longer tell muscles to move, those muscles wither away. eventually the diaphragm as well, which pulls and pushes air into the lungs. think about that. the brain is fine. but you simply cannot breathe. john knows there is no cure for als, and so does his wife, and his two daughters. >> my first thoughts were, i hated for my girls to see me go through this. >> reporter: so today is a historic day. what we're going to see is the first fda-approved clinical trial for fetal stem cells in adults. it's remarkable. obviously, a lot of issues here. dr. feldman developed the trial. >> with we inject stem cells in the spinal cord, the stem cells