Stanford researchers have identified a previously unknown immune cell that destroys nearby cells by exploding. The process unfolds so rapidly and completely that the cell disappears within minutes, leaving virtually no trace.

The discovery was made in planarian flatworms, small aquatic animals known for their extraordinary ability to regenerate. Even when cut into pieces, these worms can rebuild missing tissues and, in some cases, produce complete new organisms. Studying how their immune systems have survived and adapted over hundreds of millions of years could offer useful clues for modern medicine.

In a study published in Cell, the researchers named the newly discovered cells "ruptoblasts" because of the dramatic way they respond to a specific hormone.

"We never expected that a cell could just explode like a bomb and kill the cells surrounding it," said senior author Bo Wang, associate professor of bioengineering in the schools of Engineering and Medicine.

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