>> definitely. jon: jonathan serrie, thank you. jenna: a medical breakthrough, raising some ethical questions as well, it involves cutting edge blood test that could predict how long you live by measuring how fast your dna is aging. again, this could be just available to you and i, just to do on a monday afternoon. manny alvarez is senior managing editor of fox news health.com. >> might as well get your nails done? look, this test is a biological test, it measures the telemeters, the end part of the cells as it divides, and basically, we know in biology that the shorter the telemeter, the shorter the life span of the cell, the longer the telemeter, the longer the life span of the cell, and this is talking about aging, and it can predict more or less how long you're going live. jenna: is it accurate? >> it is very accurate but it has no practical use in medicine. jenna: what if you want to