In part 2, Dr. Riordan discusses how mesenchymal stem cells can affect tissue repair in spinal cord injury and in heart failure; benefit to heart is not the actual MSCs modeling new tissue. It is due to the trophic effects of MSC secretions; In rats, severed spinal cords re-grew after MSCs were implanted but the human MSCs did not form new cord tissue. The trophic factors secreted by the MSCs enable the spinal cord to repair itself.; Trophic factors from MSCs modulate the immune system by blocking clonal expansion of cytotoxic T-cells; There are 35 ongoing clinical trials using mesenchymal stem cells for autoimmune diseases; Safety of donor MSCs; Every mother has MSCs from each baby she has carried; Mothers have a lower incidence of autoimmune disease; Lifespan of mothers increased linearly with each child up to 14; There are 85 ongoing clinical trials using donor MSCs. Allogeneic MSCs from bone marrow have been approved in Canada and New Zealand to treat graft vs. host disease; limbal cells used in corneal transplants are MSCs; MSCs are useful in preventing donated organ rejection; glioma growth was found to be inhibited by MSCs; MSCs eliminated breast cancer in rats.