The accidental discovery of the effects of a breast milk compound, nicknamed “Hamlet” by scientists, could mean a more effective and targeted way to kill cancerous tumor cells.

Researchers from the University of Lunt in Sweden have revealed some positive results after studying the effects Hamlet has on bladder cancer patients. In the early trials, those injected with the compound began to shed dead tumor cells through their urine within days.

“There’s something magical about Hamlet’s ability to target tumor cells and kill them,” Dr. Catharina Svanborg told the Daily Mail.

But the discovery came completely by accident while the team was researching antibiotics.

“We were looking for novel antimicrobial agents, and new breast milk is a very good source of these,” Svanborg continued. “During one experiment we needed human cells and bacteria to be present, and we chose human tumor cells for practical reasons.”

“To our amazement,” she added, “when we added this compound of milk, the tumor cells died. It was a totally serendipitous discovery.”

Researchers believe that a reaction takes place with breast milk when it hits the gut. It produces a protein called alpha-lactalbumin, which targets cancer cells.

The breast milk compound targets cancer cells alone, offering an alternative to chemotherapy and radiotherapy treatments, which can damage both healthy and cancerous cells in the body.

The scientists hope the breast milk compound could also help bowel and cervical cancer patients. A trial of the Hamlet substance against a placebo is currently being planned to test the promising benefits of the compound.