A virus that typically infects black-eyed peas is showing great promise as a low-cost, potent cancer immunotherapy—and researchers are uncovering why.

In a study published in Cell Biomaterials, a team led by chemical and nano engineers at the University of California San Diego took a closer look at how the cowpea mosaic virus (CPMV), unlike other plant viruses, is uniquely effective at activating the body’s immune system to recognize and attack cancer cells.

The study is titled “Comparative analyses for plant virus-based cancer immunotherapy drug development.”