An immune system “kill switch” that destroys blood stem cells when the body is under severe stress could have implications for protecting the blood system during chemotherapy and sepsis.

In cases of sepsis or cancer patients who contract an infection, the switch is activated to kill infected stem cells and reduce the risk of infection, but too many are killed so the patient can’t recover their immune cells.

Researchers are testing inhibitors of the kill switch pathway to treat severe infections, which they hope will prevent blood cell death and treat conditions where blood stem cells are critically depleted.