Analysis of the revelation that Scottish scientists had cloned a sheep . Paul Solman reviews the year in genetics . Browse the NewsHour's index of science coverage. Well, it is possible to push a metaphor too far.
All cancers start out as a single cell that had been a loyal citizen of the republic.
Instead of converting other citizens to the cause, however, the only way the original renegade can enlarge its movement is by reproducing. The rebellious cell divides and its progeny keep dividing, each inheriting the mutated genes. Thus far, I would say the cancer cells are unrepentant anarchists. But then, some additional things happen that make the tumor more like the rival republic you suggest. Once a tumor grows beyond a certain size, it needs its own blood supply.