Survival of the fittest.

Mutagen-treated murine esophageal epithelium was used to mimic the normal aging process in humans to demonstrate an increasing patchwork of mutant clones. So much so that Notch1-mutants, for example, can often with time replace the majority of esophageal epithelium. The authors go on to lay the groundwork for a fascinating concept of an ever-evolving mutational ecosystem of sorts where mutant clones with the greatest strength in numbers, dependent on the nature of neighboring cells, either thwart or encourage malignant transformation. | Colom, Nature 2020