These lungs – taken from a mouse and seen under a high-powered confocal laser microscope – are in a bad way. The green blobs are tumours made of breast cancer cells, which have spread from their original site and set up home in the lungs. It's a common problem with advanced breast cancer in humans, especially a particularly dangerous form of the disease known as luminal breast cancer, but until now it hasn't been clear why these rogue cells decide to go on the move. It turns out that a gene called ELF5 seems to be responsible for driving cancer cells to break away from a tumour in the breast and head towards the lungs. What's more, they're resistant to hormone therapy, which is often used to treat other types of breast cancer. Figuring out exactly how ELF5 triggers cancer cells to spread could point towards life-saving new treatments.
Written by Kat Arney
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