Immortality is essentially impossible. DNA doesn't support this. We are programmed to die, either via apoptosis (preprogrammed cell death)or via our oncogenes. Our cells are not only able to kill us via tumors, but they are even able to defend themselves against drugs and against genetic engineering so far.

There are proteins in our body called multidrug resistant proteins. They are used to combat toxic substances used to mutate DNA. They also protect proteins called heat shock proteins, or stress proteins. These proteins are used to specifically protect our natural proteins which get turned on to increase hormones which kill us, with all that said you have a body that wants to die. Technology will be able to "keep us alive" but how about "living?" Not sure if that is what one could call it.

For some this may be considered immortality, breathing, having a pulse, all via machines...but if the qualityof life is not there, then I don't want any part of it.