Yasuyaki Fujita has seen first-hand what happens when cells stop being polite and start getting real. He caught a glimpse of this harsh microscopic world when he switched on a cancer-causing gene called Ras in a few kidney cells in a dish. He expected to see the cancerous cells expanding and forming the beginnings of tumours among their neighbours. Instead, the neat, orderly neighbours armed themselves with filament proteins and started “poking, poking, poking”, says Fujita, a cancer biologist at Hokkaido University in Sapporo, Japan. “The transformed cells were eliminated from the society of normal cells,” he says, literally pushed out by the cells next door.

These secret battles between your body’s cells might just save your life