harmless

"While harmless on their own, these changes could be the basic building blocks of breast cancer. With further research into how these mutations arise and accumulate, we could potentially develop new and lifesaving preventive strategies, therapeutic approaches, and routes for early detection."

Chloe Rist, Mason's sister, told the court how their family had been overprotective of him "because he was so vulnerable and harmless".

The team used a method known as optogenetics, which employs a harmless virus to deliver light-sensitive genes from microorganisms to a particular set of neurons in the brain that can be switched on and off with pulses of light.

When attempting to detect skin cancers, for example, mistakes are often made by the human examiners who confuse very similar-looking but harmless conditions with potentially fatal melanomas.

Others take it further, performing wacky, harmless stunts that will attract attention - and possible judgement from strangers - in public.