Cancer stem cells have acquired the behavior of normal stem cells by activating the same genes and pathways that make normal stem cells immortal -- except, unlike normal stem cells, they can not be lulled back into physiological sleep. Cancer, then, is quite literally, trying to emulate a regenerating organ -- or, perhaps, more disturbingly, the regenerating organism. Its quest for immortality mirrors our own quest, a quest buried in our embryos and in the renewal of our organs. Someday, if a cancer succeeds, it will produce a far more perfect being than its host -- imbued with immortality and the drive to proliferate.--- from The Emperor of All Maladies by Siddhartha Mukherjee
via The Book of Barely Imagined Beings