A compound found in tangerine peel could be used to zap cancer cells, according to a UK study.
Salvestrol Q40 is produced by plants to repel insects and fungi.
A team from the Leicester School of Pharmacy found the chemical was 20 times more toxic to cancer cells than their healthy counterparts.
Salvestrol was found in other fruit and vegetables, including broccoli and brussels sprouts.
However, the compound tends to be produced in greater quantities when infection levels among crops are high.
Lead researcher Dr Hoon Tan told the BBC: "It is very exciting to find a compound in food that can target cancers specifically.
"However, it is still early days and many tests will be needed before reaching the clinical trial stage."
Dr Julie Sharp, Cancer Research UK's science information manager, echoed his call for more tests to determine whether the compound could be developed into a cancer treatment.