Vision has an interview with Gerontology Research Group co-founder Robert Nathan: "For me, extending our healthy years is an immediate short-term step on the longer path to reverse the aging process and thereby attain physiological immortality with high quality of life, though it isn't clear how well we can avert catastrophic accidental death. Also, the big killer diseases appear to be age related: heart, cancer, stroke, Alzheimer's. If we reverse aging, do we avoid these killers? ... Over the past 50 years that I've been following this field not much real progress occurred until this last decade, starting with the mapping of the human genome. More attention has recently been focused on the mitochondria. And the most recent focus is on the control of stem cells already in our bodies. But please note, we all carry immortal cells within us. These are our germ cells, those involved with reproduction: sperm and eggs. There are also a limited number of nearly immortal stem cells. The rest of our body is composed of somatic cells that no longer divide and tend to die under some kind of programmed control. When I was young, the medical dogma declared that muscle, neural and kidney cells no longer increase in number once we mature. Today all that has been reversed. We have always had in our bodies different kinds of nearly immortal stem cells, which can replenish all three of these tissues on demand."