Viruses such as measles (pictured here) can be used to attack cancerous cells. Credit: Eye Of Science/Science Photo LibraryA scientist who successfully treated her own breast cancer by injecting the tumour with lab-grown viruses has sparked discussion about the ethics of self-experimentation. Beata Halassy discovered in 2020, aged 49, that she had breast cancer at the site of a previous mastectomy. It was the second recurrence there since her left breast had been removed, and she couldn’t face a...